JAVA Proxy

Java打印代理模式实现及应用

最新推荐文章于 2025-09-12 18:08:49 发布

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最新推荐文章于 2025-09-12 18:08:49 发布

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CC 4.0 BY-SA版权

文章标签： java string class object interface null

本文链接：https://blog.youkuaiyun.com/zhoushuai520/article/details/6722530

本文详细介绍了Java中代理模式的实现，包括基础类Printer和代理类PrinterProxy的功能实现和交互过程，通过实例展示了如何使用代理模式进行打印任务的管理和优化。

/**
*
*/
package patterns.proxy;

/**
* @author zhouushe
*
*/
public interface Printable {
public abstract void setprinterName(String name);

public abstract String getPrinterName();

public abstract void print(String string);

}

=================================================================================================

package patterns.proxy;

/**
* @author zhouushe
*
*/
public class Printer implements Printable {
private String name;

public Printer() {
this.heavyJob("Be producing object instance...");
}

public Printer(String name){
this.name = name;
this.heavyJob("Be producing object instance " + this.name + "...");
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#setprinterName(java.lang.String)
*/
@Override
public void setprinterName(String name) {
this.name = name;
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#getPrinterName()
*/
@Override
public String getPrinterName() {
return this.name;
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#print(java.lang.String)
*/
@Override
public void print(String string) {
System.out.println("=== " + this.name + " ===");
System.out.println(string);
}

private void heavyJob(String msg) {
System.out.print(msg);
for (int i = 0; i < 5; i++) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.print(".");
}
System.out.println("Finish...");
}

}

=================================================================================================

package patterns.proxy;

/**
* @author zhouushe
*
*/
public class PrinterProxy implements Printable {
private String name;
private Printer real;

public PrinterProxy() {

}

public PrinterProxy(String name) {
this.name = name;
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#setprinterName(java.lang.String)
*/
@Override
public synchronized void setprinterName(String name) {
if (this.real != null) {
this.real.setprinterName(name);
}
this.name = name;
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#getPrinterName()
*/
@Override
public String getPrinterName() {
// TODO Auto-generated method stub
return this.name;
}

/*
* (non-Javadoc)
*
* @see patterns.proxy.Printable#print(java.lang.String)
*/
@Override
public void print(String string) {
this.realize();
this.real.print(string);
}

private synchronized void realize() {
if (this.real == null) {
this.real = new Printer(this.name);
}
}

}

=================================================================================================

package patterns.proxy;

/**
* @author zhouushe
*
*/
public class Main {
public static void main(String[] args) {
Printable p = new PrinterProxy("Alice");
System.out.println("Current name is: " + p.getPrinterName() + ".");
p.setprinterName("Bob");
System.out.println("Current name is: " + p.getPrinterName() + ".");
p.print("Hello, World!");
}
}