midlet4.java

这是郭克华老师的J2ME视频的源代码

package prj15_1;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;

import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.rms.RecordStore;

public class MIDlet4 extends MIDlet {

	protected void startApp() throws MIDletStateChangeException {
		RecordStore rs = null;
		try{
			rs = RecordStore.openRecordStore("RS1", true);
			Customer cus = new Customer();
			cus.setCname("王强");
			cus.setPhone("02567823456");
			cus.setAge(34);
			//转换为字节数组写入
			byte[] b1 = cus.object2ByteArray();
			rs.addRecord(b1, 0, b1.length);
			//读
			byte[] b2 = rs.getRecord(1);
			Customer newCus = Customer.byteArray2Object(b2);
			System.out.println(newCus.getCname());
			System.out.println(newCus.getAge());
			

		}catch(Exception ex){
			ex.printStackTrace();
		}
		finally{
			try{
				rs.closeRecordStore();
			}catch(Exception ex){}
		}
		

	}
	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
		// TODO Auto-generated method stub

	}

	protected void pauseApp() {
		// TODO Auto-generated method stub

	}
}
class Customer{
	private String cname;
	private String phone;
	private int age;
	//将对象转为字节数组
	public byte[] object2ByteArray() throws Exception{
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		DataOutputStream dos = new DataOutputStream(baos);
		
		//通过dos将对象内容写入baos
		dos.writeUTF(this.cname);
		dos.writeUTF(this.phone);
		dos.writeInt(this.age);
		baos.close();
		dos.close();
		
		return baos.toByteArray();//返回字节数组
	}
	//将字节数组转为对象
	public static Customer byteArray2Object(byte[] b) throws Exception{
		ByteArrayInputStream bais = new ByteArrayInputStream(b);
		DataInputStream dis = new DataInputStream(bais);
		//从bais读取内容
		Customer cus = new Customer();
		cus.setCname(dis.readUTF());
		cus.setPhone(dis.readUTF());
		cus.setAge(dis.readInt());
		bais.close();
		dis.close();
		return cus;
	}
	
	public String getCname() {
		return cname;
	}
	public void setCname(String cname) {
		this.cname = cname;
	}
	public String getPhone() {
		return phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}