《JAVA与模式》第25天―解释器模式 - JAVA

)类定义出从变量到布尔值的一个映射
*/
public class Context {

private Map map = new HashMap();

public void assign(Variable var, boolean value) {
map.put(var, new Boolean(value));
}

public boolean lookup(Variable var) throws IllegalArgumentException {
Boolean value = map.get(var);
if (value == null) {
throw new IllegalArgumentException();
}
return value.booleanValue();
}
}
package com.bankht.Interpreter;

import java.util.HashMap;
import java.util.Map;

/**
* @author: 特种兵—AK47
* @创建时间：2012-7-3 下午03:11:54
*
* @类说明：环境(Context)类定义出从变量到布尔值的一个映射
*/
public class Context {

private Map map = new HashMap();

public void assign(Variable var, boolean value) {
map.put(var, new Boolean(value));
}

public boolean lookup(Variable var) throws IllegalArgumentException {
Boolean value = map.get(var);
if (value == null) {
throw new IllegalArgumentException();
}
return value.booleanValue();
}
}

　　客户端类

[java]
package com.bankht.Interpreter;

/**
* @author: 特种兵—AK47
* @创建时间：2012-7-3 下午03:12:17
*
* @类说明：客户端类
*/
public class Client {

public static void main(String[] args) {
Context ctx = new Context();
Variable x = new Variable("x");
Variable y = new Variable("y");
Constant c = new Constant(true);
ctx.assign(x, false);
ctx.assign(y, true);

Expression exp = new Or(new And(c, x), new And(y, new Not(x)));
System.out.println("x=" + x.interpret(ctx));
System.out.println("y=" + y.interpret(ctx));
System.out.println(exp.toString() + "=" + exp.interpret(ctx));
}

}
package com.bankht.Interpreter;

/**
* @author: 特种兵—AK47
* @创建时间：2012-7-3 下午03:12:17
*
* @类说明：客户端类
*/
public class Client {

public static void main(String[] args) {
Context ctx = new Context();
Variable x = new Variable("x");
Variable y = new Variable("y");
Constant c = new Constant(true);
ctx.assign(x, false);
ctx.assign(y, true);

Expression exp = new Or(new And(c, x), new And(y, new Not(x)));
System.out.println("x=" + x.interpret(ctx));
System.out.println("y=" + y.interpret(ctx));
System.out.println(exp.toString() + "=" + exp.interpret(ctx));
}

}

　　运行结果如下：

[html]
x=false
y=true
((true AND x) OR (y AND (Not x)))=true
　作者：m13666368773

《JAVA与模式》第25天―解释器模式 (三)