java读写二进制文件的解决方法

2022-10-20,,,

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。

《java读写二进制文件的解决方法.doc》

下载本文的Word格式文档,以方便收藏与打印。