Google Guice的施用

Google Guice的使用

本文通过范例简单地介绍Google Guice的使用,通过下面的范例我们可以知道,Google Guice的使用非常简单。

Google Guice需要使用JDK1.5以上java环境。

下载Google Guice之后,

有以下几个文件:

aopalliance.jar

guice-1.0.jar

guice-servlet-1.0.jar

guice-spring-1.0.jar

guice-struts2-plugin-1.0.jar

本例只使用到guice-1.0.jar文件,将其加入到class path中。

下面简单地介绍范例:

范例1:使用com.google.inject.Module接口实现类

文件名 说明
HelloGuice.java 业务逻辑接口定义文件
HelloGuiceImpl.java 业务逻辑接口实现文件
HelloGuiceModule.java 该文件必须实现com.google.inject.Module接口
TestGuice.java 测试文件

 

 

HelloGuice.java

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package com.test.guice;

public interface HelloGuice {
  public void sayHello();
}

package com.test.guice;

public interface HelloGuice {
  public void sayHello();
}

HelloGuiceImpl.java

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package com.test.guice;

public class HelloGuiceImpl implements HelloGuice {

  public void sayHello() {
    System.out.println("Hello Guice!");
  }
}

package com.test.guice;

public class HelloGuiceImpl implements HelloGuice {

  public void sayHello() {
    System.out.println("Hello Guice!");
  }
}

HelloGuiceModule.java

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package com.test.guice;

import com.google.inject.Binder;
import com.google.inject.Module;

public class HelloGuiceModule implements Module {

  public void configure(Binder binder) {
    binder.bind(HelloGuice.class).to(HelloGuiceImpl.class);
  }

}

package com.test.guice;

import com.google.inject.Binder;
import com.google.inject.Module;

public class HelloGuiceModule implements Module {

  public void configure(Binder binder) {
    binder.bind(HelloGuice.class).to(HelloGuiceImpl.class);
  }

}

TestGuice.java

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package com.test.guice;

import junit.framework.TestCase;

import com.google.inject.Guice;
import com.google.inject.Injector;

public class TestGuice extends TestCase {
  public void testHelloGuice() {
    Injector injector = Guice.createInjector(new HelloGuiceModule());

    HelloGuice helloGuice = injector.getInstance(HelloGuice.class);
    helloGuice.sayHello();
  }
}

package com.test.guice;

import junit.framework.TestCase;

import com.google.inject.Guice;
import com.google.inject.Injector;

public class TestGuice extends TestCase {
  public void testHelloGuice() {
    Injector injector = Guice.createInjector(new HelloGuiceModule());

    HelloGuice helloGuice = injector.getInstance(HelloGuice.class);
    helloGuice.sayHello();
  }
}

 


运行TestGuice,打印出:

Hello Guice!

范例2:使用Java Annotation

我们也可以直接为HelloGuice加上@ImplementedBy注释,而省略掉对com.google.inject.Module的实现。

 

HelloGuice.java

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package com.test.guice;

import com.google.inject.ImplementedBy;

@ImplementedBy(HelloGuiceImpl.class)
public interface HelloGuice {
  public void sayHello();
}

package com.test.guice;

import com.google.inject.ImplementedBy;

@ImplementedBy(HelloGuiceImpl.class)
public interface HelloGuice {
  public void sayHello();
}

TestGuice.java

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package com.test.guice;

import junit.framework.TestCase;

import com.google.inject.Guice;
import com.google.inject.Injector;

public class TestGuice extends TestCase {
  public void testHelloGuice() {
    //Injector injector = Guice.createInjector(new HelloGuiceModule());

    Injector injector = Guice.createInjector();
    HelloGuice helloGuice = injector.getInstance(HelloGuice.class);
    helloGuice.sayHello();
  }
}

package com.test.guice;

import junit.framework.TestCase;

import com.google.inject.Guice;
import com.google.inject.Injector;

public class TestGuice extends TestCase {
  public void testHelloGuice() {
    //Injector injector = Guice.createInjector(new HelloGuiceModule());

    Injector injector = Guice.createInjector();
    HelloGuice helloGuice = injector.getInstance(HelloGuice.class);
    helloGuice.sayHello();
  }
}

 HelloGuiceModule.java不再需要。其余的文件内容不变。

运行TestGuice,打印出:

Hello Guice!

本文通过范例简单地介绍了Google Guice的使用。至于Google Guice与Spring,Struts等的集成,本文未加涉及,请参考其他文章。