Java by API/java.io/PrintWriter — различия между версиями

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м (1 версия)
 
(нет различий)

Текущая версия на 14:32, 31 мая 2010

new PipedWriter()

  
import java.io.IOException;
import java.io.PipedReader;
import java.io.PipedWriter;
public class Main {
  public static void main(String[] args) throws IOException {
    PipedWriter pw = new PipedWriter();
    PipedReader pr = new PipedReader(pw);
    int ch;
    try {
      for (int i = 0; i < 15; i++)
        pw.write(" A" + i + "\n");
      while ((ch = pr.read()) != -1)
        System.out.print((char) ch);
    } catch (IOException e) {
    }
  }
}





new PrintWriter(BufferedWriter, boolean autoFlush)

   
/*
 * Output: 
 *  
 */
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.PrintWriter;
public class MainClass {
  public static void main(String args[]) {
    try {
      // Create a print writer
      FileWriter fw = new FileWriter(args[0]);
      BufferedWriter bw = new BufferedWriter(fw);
      PrintWriter pw = new PrintWriter(bw, false);
      // Experiment with some methods
      pw.println(true);
      pw.println("A");
      pw.println(500);
      pw.println(40000L);
      pw.println(45.67f);
      pw.println(45.67);
      pw.println("Hello");
      pw.println(new Integer("99"));
      // Close print writer
      pw.close();
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
  }
}





new PrintWriter(Writer out)

 
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
public class Main {
  public static void main(String[] args) {
    try {
      BufferedReader input = new BufferedReader(new FileReader(args[0]));
      ArrayList list = new ArrayList();
      String line;
      while ((line = input.readLine()) != null) {
        list.add(line);
      }
      input.close();
      Collections.reverse(list);
      PrintWriter output = new PrintWriter(new BufferedWriter(new FileWriter(args[1])));
      for (Iterator i = list.iterator(); i.hasNext();) {
        output.println((String) i.next());
      }
      output.close();
    } catch (IOException e) {
      System.err.println(e);
    }
  }
}





PrintWriter: close()

   

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class Main {
  public static void main(String[] args) {
    try {
      char[] chars = new char[2];
      chars[0] = "\u4F60";
      chars[1] = "\u597D";
      String encoding = "GB18030";
      File textFile = new File("C:\\temp\\myFile.txt");
      PrintWriter writer = new PrintWriter(textFile,encoding);
      writer.write(chars);
      writer.close();
      // read back
      InputStreamReader reader = new InputStreamReader(new FileInputStream(textFile), encoding);
      char[] chars2 = new char[2];
      reader.read(chars2);
      System.out.print(chars2[0]);
      System.out.print(chars2[1]);
      reader.close();
    } catch (IOException e) {
      System.out.println(e.toString());
    }
  }
}





PrintWriter: print(char c)

 
import java.io.FileWriter;
import java.io.PrintWriter;
public class Main {
  public static void main() throws Exception{
    PrintWriter pw = new PrintWriter(new FileWriter("dice.txt"));
    for (int i = 1; i <= 1000; i++) {
      int die = (int) (1 + 6 * Math.random());
      pw.print(die);
      pw.print(" ");
      if (i % 20 == 0)
        pw.println();
    }
    pw.println();
    pw.close(); // Without this, the output file may be empty
  }
}





PrintWriter: print(int i)

 
import java.io.FileWriter;
import java.io.PrintWriter;
public class Main {
  public static void main() throws Exception{
    PrintWriter pw = new PrintWriter(new FileWriter("dice.txt"));
    for (int i = 1; i <= 1000; i++) {
      int die = (int) (1 + 6 * Math.random());
      pw.print(die);
      pw.print(" ");
      if (i % 20 == 0)
        pw.println();
    }
    pw.println();
    pw.close(); // Without this, the output file may be empty
  }
}





PrintWriter: println()

   
/*
 * Output:
true
A
500
40000
45.67
45.67
Hello
99
 
 */
import java.io.PrintWriter;
public class MainClass {
  public static void main(String args[]) {
    try {
      PrintWriter pw = new PrintWriter(System.out);
      // Experiment with some methods
      pw.println(true);
      pw.println("A");
      pw.println(500);
      pw.println(40000L);
      pw.println(45.67f);
      pw.println(45.67);
      pw.println("Hello");
      pw.println(new Integer("99"));
      // Close print writer
      pw.close();
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
  }
}





PrintWriter: println(char x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





PrintWriter: println(double x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





PrintWriter: println(float x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





PrintWriter: println(int x)

 
import java.io.IOException;
import java.io.PrintWriter;
public class Main {
  public static void main(String[] args) {
    try {
      PrintWriter pw = new PrintWriter("c:\\temp\\printWriterOutput.txt");
      pw.println("PrintWriter is easy to use.");
      pw.println(1234);
      pw.close();
    } catch (IOException e) {
    }
  }
}





PrintWriter: println(long x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





PrintWriter: println(Object x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





PrintWriter: println(String x)

 

import java.io.PrintWriter;
public class Main {
  public static void main(String args[]) throws Exception {
    PrintWriter pw = new PrintWriter(System.out);
    // Experiment with some methods
    pw.println(true);
    pw.println("A");
    pw.println(500);
    pw.println(40000L);
    pw.println(45.67f);
    pw.println(45.67);
    pw.println("Hello");
    pw.println(new Integer("99"));
    // Close print writer
    pw.close();
  }
}





Writer: write(char[] cbuf)

   
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
public class Main {
  public static void main(String[] args) {
    try {
      char[] chars = new char[2];
      chars[0] = "\u4F60";
      chars[1] = "\u597D";
      String encoding = "GB18030";
      File textFile = new File("C:\\temp\\myFile.txt");
      OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(textFile), encoding);
      writer.write(chars);
      writer.close();
    } catch (IOException e) {
      System.out.println(e.toString());
    }
  }
}