【转】java读写二进制文件的解决方法

原文网址：http://www.jb51.net/article/36940.htm

接口：Writerable

复制代码代码如下:

package com.geoway.pad.common;

import java.io.DataInput; 
import java.io.DataOutput; 
import java.io.IOException;

public interface Writerable { 
       //write  
       public void  write(DataOutput data) throws IOException; 
       //read 
       public  void read(DataInput di) throws IOException; 
}

接口实现类：UserWriter

复制代码代码如下:

package com.geoway.pad.common;

import java.io.ByteArrayInputStream; 
import java.io.ByteArrayOutputStream; 
import java.io.DataInput; 
import java.io.DataInputStream; 
import java.io.DataOutput; 
import java.io.DataOutputStream; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.util.UUID;

public class UserWriter implements Writerable{ 
    //getter  setter  methods 
    public int getNumber() { 
        return number; 
    } 
    public void setNumber(int number) { 
        this.number = number; 
    } 
    public String getId() { 
        return id; 
    } 
    public void setId(String id) { 
        this.id = id; 
    } 
    public int getAge() { 
        return age; 
    } 
    public void setAge(int age) { 
        this.age = age; 
    } 
    public boolean isAdministrator() { 
        return administrator; 
    } 
    public void setAdministrator(boolean administrator) { 
        this.administrator = administrator; 
    } 
    public String getUserName() { 
        return userName; 
    } 
    public void setUserName(String userName) { 
        this.userName = userName; 
    } 
    public void setPassword(String password) { 
        this.password = password; 
    } 
    public String getPassword() { 
        return password; 
    } 
    public void setText(String text) { 
        this.text = text; 
    } 
    public String getText() { 
        return text; 
    } 
    public void setImage(byte[] image) { 
        this.image = image; 
    } 
    public byte[] getImage() { 
        return image; 
    }; 
    //private  fields 
     private int number; 
     private String id; 
     private int age; 
     private boolean administrator; 
     private  String userName; 
     private  String password; 
     private  String text; 
     private  byte[]  image;

@Override
    public void write(DataOutput data) throws IOException { 
       data.writeInt(number); 
       data.writeUTF(id); 
       data.writeInt(age); 
       data.writeBoolean(administrator); 
       data.writeUTF(userName); 
       data.writeUTF(password); 
       data.writeUTF(text); 
       data.write(image);

} 
    @Override
    public void read(DataInput di) throws IOException { 
       this.number=di.readInt(); 
       this.id=di.readUTF(); 
       this.age=di.readInt(); 
       this.administrator=di.readBoolean(); 
       this.userName=di.readUTF(); 
       this.password=di.readUTF(); 
       this.text=di.readUTF(); 
       //读取图片 
       this.image=new byte[2048]; 
       try{ 
         di.readFully(this.image); 
       }catch(Exception e){ 
           System.out.println(e.toString()); 
       } 
    } 
  public static byte[] in2byte(InputStream is) throws IOException{   
     byte[] bs= new byte[1024];   
     ByteArrayOutputStream bos = new ByteArrayOutputStream();   
     int len = -1;   
     while((len=is.read(bs))!=-1){   
         bos.write(bs,0,len);   
     }   
     bs = bos.toByteArray() ;   
     return bs ;   
   }   
   public static  void copy(InputStream in, OutputStream out) throws IOException {   
       byte[] buf = new byte[1024];   
       while (true) {   
                int len = in.read(buf);   
                   if (len < 0) break;   
          out.write(buf, 0, len);   
          }   
  }   
 public  static  void main(String[] args) throws FileNotFoundException, IOException{ 
        UserWriter user=new UserWriter(); 
        user.setUserName("likehua"); 
        user.setPassword("password"); 
        user.setId(UUID.randomUUID().toString()); 
        user.setNumber(123); 
        user.setAdministrator(false); 
        //加一段文字 
        user.setText("做一个天气预报，可以保存要显示的城市名称 在增加城市页面，我的rms关键操作如下（其中SetCanvas.cityName是一个Vector，用来保存城市名，在执行此段代码之前，我已经把新增加的城市名添加进了这个Vector "); 
        //传入一张图片 
        user.setImage(in2byte(new FileInputStream("c:\\1.jpg"))); 
        user.write(new DataOutputStream(new FileOutputStream("c:\\user.data"))); 
        System.out.println("完毕");        
        System.out.println("....读取开始..."); 
        UserWriter u=new UserWriter(); 
        u.read(new DataInputStream(new FileInputStream("c:\\user.data"))); 
        System.out.println(u.getUserName()); 
        System.out.println(u.getPassword()); 
        System.out.println(u.isAdministrator()); 
        System.out.println(u.getText()); 
        //拿出图片 
        copy(new ByteArrayInputStream(u.getImage()), new FileOutputStream("c:\\copy.jpg"));

}

}

本例只是本人测试DataOutput和DataInput接口时写的，并没有在项目中使用，也不知道在项目中这样用会不会有什么问题。