Java Tutorial/Data Type/String Join
Версия от 17:44, 31 мая 2010; (обсуждение)
Содержание
- 1 Join an array of strings into one delimited string
- 2 Joins array elements into a single String: specify the start index and end index.
- 3 Joins array elements into a single String without specifying the start index and end index.
- 4 Joins array elements: Null objects or empty strings within the array are represented by empty strings.
- 5 Joins the elements of Collection into a single String with string separator.
- 6 Joins the elements of the provided array into a single String containing the provided list of elements.
- 7 Joins the elements of the provided Collection into a single String containing the provided elements.
- 8 Joins the elements of the provided Iterator into a single String containing the provided elements.
- 9 Join String
- 10 Join string from soapUI
- 11 Overlays part of a String with another String.
Join an array of strings into one delimited string
/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
public class Main{
/////////////////////////////////////////////////////////////////////////
// Joining/Concatenation Methods //
/////////////////////////////////////////////////////////////////////////
/**
* Join an array of strings into one delimited string.
*
* @param buff String buffered used for join (buffer is not reset).
* @param array Array of objects to join as strings.
* @param delim Delimiter to join strings with or <i>null</i>.
* @return Joined string.
*/
public static String join(final StringBuffer buff, final Object array[],
final String delim)
{
boolean haveDelim = (delim != null);
for (int i = 0; i < array.length; i++)
{
buff.append(array[i]);
// if this is the last element then don"t append delim
if (haveDelim && (i + 1) < array.length)
{
buff.append(delim);
}
}
return buff.toString();
}
/**
* Join an array of strings into one delimited string.
*
* @param array Array of objects to join as strings.
* @param delim Delimiter to join strings with or <i>null</i>.
* @return Joined string.
*/
public static String join(final Object array[], final String delim)
{
return join(new StringBuffer(), array, delim);
}
/**
* Convert and join an array of objects into one string.
*
* @param array Array of objects to join as strings.
* @return Converted and joined objects.
*/
public static String join(final Object array[])
{
return join(array, null);
}
/**
* Convert and join an array of bytes into one string.
*
* @param array Array of objects to join as strings.
* @return Converted and joined objects.
*/
public static String join(final byte array[])
{
Byte bytes[] = new Byte[array.length];
for (int i = 0; i < bytes.length; i++)
{
bytes[i] = new Byte(array[i]);
}
return join(bytes, null);
}
/**
* Return a string composed of the given array.
*
* @param buff Buffer used to construct string value (not reset).
* @param array Array of objects.
* @param prefix String prefix.
* @param separator Element sepearator.
* @param suffix String suffix.
* @return String in the format of:
* prefix + n ( + separator + n+i)* + suffix.
*/
public static String join(final StringBuffer buff, final Object[] array,
final String prefix, final String separator,
final String suffix)
{
buff.append(prefix);
join(buff, array, separator);
buff.append(suffix);
return buff.toString();
}
/**
* Return a string composed of the given array.
*
* @param array Array of objects.
* @param prefix String prefix.
* @param separator Element sepearator.
* @param suffix String suffix.
* @return String in the format of:
* prefix + n ( + separator + n+i)* + suffix.
*/
public static String join(final Object[] array, final String prefix,
final String separator, final String suffix)
{
return join(new StringBuffer(), array, prefix, separator, suffix);
}
}
Joins array elements into a single String: specify the start index and end index.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ",") = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
if (separator == null) {
separator = "";
}
// endIndex - startIndex > 0: Len = NofStrings *(len(firstString) + len(separator))
// (Assuming that all Strings are roughly equally long)
int bufSize = (endIndex - startIndex);
if (bufSize <= 0) {
return "";
}
bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length())
+ separator.length());
StringBuffer buf = new StringBuffer(bufSize);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
}
Joins array elements into a single String without specifying the start index and end index.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ",") = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ",") = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
if (separator == null) {
separator = "";
}
// endIndex - startIndex > 0: Len = NofStrings *(len(firstString) + len(separator))
// (Assuming that all Strings are roughly equally long)
int bufSize = (endIndex - startIndex);
if (bufSize <= 0) {
return "";
}
bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length())
+ separator.length());
StringBuffer buf = new StringBuffer(bufSize);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
}
Joins array elements: Null objects or empty strings within the array are represented by empty strings.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No separator is added to the joined String.
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null) = null
* StringUtils.join([]) = ""
* StringUtils.join([null]) = ""
* StringUtils.join(["a", "b", "c"]) = "abc"
* StringUtils.join([null, "", "a"]) = "a"
* </pre>
*
* @param array the array of values to join together, may be null
* @return the joined String, <code>null</code> if null array input
* @since 2.0
*/
public static String join(Object[] array) {
return join(array, null);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ",") = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ",") = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
if (separator == null) {
separator = "";
}
// endIndex - startIndex > 0: Len = NofStrings *(len(firstString) + len(separator))
// (Assuming that all Strings are roughly equally long)
int bufSize = (endIndex - startIndex);
if (bufSize <= 0) {
return "";
}
bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length())
+ separator.length());
StringBuffer buf = new StringBuffer(bufSize);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
}
Joins the elements of Collection into a single String with string separator.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided <code>Collection</code> into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
*
* See the examples here: {@link #join(Object[],String)}.
*
* @param collection the <code>Collection</code> of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null iterator input
* @since 2.3
*/
public static String join(Collection collection, String separator) {
if (collection == null) {
return null;
}
return join(collection.iterator(), separator);
}
/**
* Joins the elements of the provided <code>Iterator</code> into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
*
* See the examples here: {@link #join(Object[],String)}.
*
* @param iterator the <code>Iterator</code> of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null iterator input
*/
public static String join(Iterator iterator, String separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return "";
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return toString(first);
}
// two or more elements
StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
if (separator != null) {
buf.append(separator);
}
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
// ToString
//-----------------------------------------------------------------------
/**
* Gets the <code>toString</code> of an <code>Object</code> returning
* an empty string ("") if <code>null</code> input.
*
* <pre>
* ObjectUtils.toString(null) = ""
* ObjectUtils.toString("") = ""
* ObjectUtils.toString("bat") = "bat"
* ObjectUtils.toString(Boolean.TRUE) = "true"
* </pre>
*
* @see StringUtils#defaultString(String)
* @see String#valueOf(Object)
* @param obj the Object to <code>toString</code>, may be null
* @return the passed in Object"s toString, or nullStr if <code>null</code> input
* @since 2.0
*/
public static String toString(Object obj) {
return obj == null ? "" : obj.toString();
}
}
Joins the elements of the provided array into a single String containing the provided list of elements.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], ";") = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ";") = ";;a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, <code>null</code> if null array input
* @since 2.0
*/
public static String join(Object[] array, char separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* Null objects or empty strings within the array are represented by
* empty strings.
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], ";") = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ";") = ";;a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, <code>null</code> if null array input
* @since 2.0
*/
public static String join(Object[] array, char separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
int bufSize = (endIndex - startIndex);
if (bufSize <= 0) {
return "";
}
bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length()) + 1);
StringBuffer buf = new StringBuffer(bufSize);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
}
Joins the elements of the provided Collection into a single String containing the provided elements.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided <code>Collection</code> into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.
*
* See the examples here: {@link #join(Object[],char)}.
*
* @param collection the <code>Collection</code> of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, <code>null</code> if null iterator input
* @since 2.3
*/
public static String join(Collection collection, char separator) {
if (collection == null) {
return null;
}
return join(collection.iterator(), separator);
}
/**
* Joins the elements of the provided <code>Iterator</code> into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.
*
* See the examples here: {@link #join(Object[],char)}.
*
* @param iterator the <code>Iterator</code> of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, <code>null</code> if null iterator input
* @since 2.0
*/
public static String join(Iterator iterator, char separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return "";
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return toString(first);
}
// two or more elements
StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
buf.append(separator);
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
// ToString
//-----------------------------------------------------------------------
/**
* Gets the <code>toString</code> of an <code>Object</code> returning
* an empty string ("") if <code>null</code> input.
*
* <pre>
* ObjectUtils.toString(null) = ""
* ObjectUtils.toString("") = ""
* ObjectUtils.toString("bat") = "bat"
* ObjectUtils.toString(Boolean.TRUE) = "true"
* </pre>
*
* @see StringUtils#defaultString(String)
* @see String#valueOf(Object)
* @param obj the Object to <code>toString</code>, may be null
* @return the passed in Object"s toString, or nullStr if <code>null</code> input
* @since 2.0
*/
public static String toString(Object obj) {
return obj == null ? "" : obj.toString();
}
}
Joins the elements of the provided Iterator into a single String containing the provided elements.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class Main {
/**
* Joins the elements of the provided <code>Iterator</code> into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").
*
* See the examples here: {@link #join(Object[],String)}.
*
* @param iterator the <code>Iterator</code> of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null iterator input
*/
public static String join(Iterator iterator, String separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return "";
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return toString(first);
}
// two or more elements
StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
if (separator != null) {
buf.append(separator);
}
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
// ToString
//-----------------------------------------------------------------------
/**
* Gets the <code>toString</code> of an <code>Object</code> returning
* an empty string ("") if <code>null</code> input.
*
* <pre>
* ObjectUtils.toString(null) = ""
* ObjectUtils.toString("") = ""
* ObjectUtils.toString("bat") = "bat"
* ObjectUtils.toString(Boolean.TRUE) = "true"
* </pre>
*
* @see StringUtils#defaultString(String)
* @see String#valueOf(Object)
* @param obj the Object to <code>toString</code>, may be null
* @return the passed in Object"s toString, or nullStr if <code>null</code> input
* @since 2.0
*/
public static String toString(Object obj) {
return obj == null ? "" : obj.toString();
}
}
Join String
/*
* Static String formatting and query routines.
* Copyright (C) 2001-2005 Stephen Ostermiller
* http://ostermiller.org/contact.pl?regarding=Java+Utilities
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* See COPYING.TXT for details.
*/
import java.util.HashMap;
import java.util.regex.Pattern;
/**
* Utilities for String formatting, manipulation, and queries.
* More information about this class is available from .
*
* @author Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities
* @since ostermillerutils 1.00.00
*/
public class StringHelper {
/**
* Join all the elements of a string array into a single
* String.
*
* If the given array empty an empty string
* will be returned. Null elements of the array are allowed
* and will be treated like empty Strings.
*
* @param array Array to be joined into a string.
* @return Concatenation of all the elements of the given array.
* @throws NullPointerException if array is null.
*
* @since ostermillerutils 1.05.00
*/
public static String join(String[] array){
return join(array, "");
}
/**
* Join all the elements of a string array into a single
* String.
*
* If the given array empty an empty string
* will be returned. Null elements of the array are allowed
* and will be treated like empty Strings.
*
* @param array Array to be joined into a string.
* @param delimiter String to place between array elements.
* @return Concatenation of all the elements of the given array with the the delimiter in between.
* @throws NullPointerException if array or delimiter is null.
*
* @since ostermillerutils 1.05.00
*/
public static String join(String[] array, String delimiter){
// Cache the length of the delimiter
// has the side effect of throwing a NullPointerException if
// the delimiter is null.
int delimiterLength = delimiter.length();
// Nothing in the array return empty string
// has the side effect of throwing a NullPointerException if
// the array is null.
if (array.length == 0) return "";
// Only one thing in the array, return it.
if (array.length == 1){
if (array[0] == null) return "";
return array[0];
}
// Make a pass through and determine the size
// of the resulting string.
int length = 0;
for (int i=0; i<array.length; i++){
if (array[i] != null) length+=array[i].length();
if (i<array.length-1) length+=delimiterLength;
}
// Make a second pass through and concatenate everything
// into a string buffer.
StringBuffer result = new StringBuffer(length);
for (int i=0; i<array.length; i++){
if (array[i] != null) result.append(array[i]);
if (i<array.length-1) result.append(delimiter);
}
return result.toString();
}
}
Join string from soapUI
/*
* soapUI, copyright (C) 2004-2009 eviware.ru
*
* soapUI is free software; you can redistribute it and/or modify it under the
* terms of version 2.1 of the GNU Lesser General Public License as published by
* the Free Software Foundation.
*
* soapUI is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details at gnu.org.
*/
public class Utils {
public static String join( String[] array, String separator )
{
StringBuffer buf = new StringBuffer();
for( int i = 0; i < array.length; i++ )
{
if( i > 0 )
buf.append( separator );
buf.append( array[i] );
}
return buf.toString();
}
}
Overlays part of a String with another String.
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*
*/
public class Main {
/**
* Overlays part of a String with another String.
*
* A <code>null</code> string input returns <code>null</code>.
* A negative index is treated as zero.
* An index greater than the string length is treated as the string length.
* The start index is always the smaller of the two indices.
*
* <pre>
* StringUtils.overlay(null, *, *, *) = null
* StringUtils.overlay("", "abc", 0, 0) = "abc"
* StringUtils.overlay("abcdef", null, 2, 4) = "abef"
* StringUtils.overlay("abcdef", "", 2, 4) = "abef"
* StringUtils.overlay("abcdef", "", 4, 2) = "abef"
* StringUtils.overlay("abcdef", "zzzz", 2, 4) = "abzzzzef"
* StringUtils.overlay("abcdef", "zzzz", 4, 2) = "abzzzzef"
* StringUtils.overlay("abcdef", "zzzz", -1, 4) = "zzzzef"
* StringUtils.overlay("abcdef", "zzzz", 2, 8) = "abzzzz"
* StringUtils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef"
* StringUtils.overlay("abcdef", "zzzz", 8, 10) = "abcdefzzzz"
* </pre>
*
* @param str the String to do overlaying in, may be null
* @param overlay the String to overlay, may be null
* @param start the position to start overlaying at
* @param end the position to stop overlaying before
* @return overlayed String, <code>null</code> if null String input
* @since 2.0
*/
public static String overlay(String str, String overlay, int start, int end) {
if (str == null) {
return null;
}
if (overlay == null) {
overlay = "";
}
int len = str.length();
if (start < 0) {
start = 0;
}
if (start > len) {
start = len;
}
if (end < 0) {
end = 0;
}
if (end > len) {
end = len;
}
if (start > end) {
int temp = start;
start = end;
end = temp;
}
return new StringBuffer(len + start - end + overlay.length() + 1)
.append(str.substring(0, start))
.append(overlay)
.append(str.substring(end))
.toString();
}
}
