java讀寫二進位檔案

介面：Writerable

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;}

 介面實作類別：UserWriter

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  methodspublic 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;@Overridepublic 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);}@Overridepublic 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();       //讀取圖片       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("做一個天氣預報，可以儲存要顯示的城市名稱 在增加城市頁面，我的rms關鍵操作如下（其中SetCanvas.cityName是一個Vector，用來儲存城市名，在執行此段代碼之前，我已經把新增加的城市名添加進了這個Vector ");        //傳入一張圖片        user.setImage(in2byte(new FileInputStream("c:\\1.jpg")));user.write(new DataOutputStream(new FileOutputStream("c:\\user.data")));System.out.println("完畢");System.out.println("....讀取開始...");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());//拿出圖片copy(new ByteArrayInputStream(u.getImage()), new FileOutputStream("c:\\copy.jpg"));}}

 本例  只是本人測試DataOutput和DataInput介面時寫的   並沒有在項目中使用   也不知道在項目中這樣用 會不會有什麼問題。