Groovy补充

Java中运行Groovy,有三种比较常用的类支持

• GroovyShell
  • 通常用来运行"script片段"或者一些零散的表达式(Expression)
• GroovyClassLoader
  • 如果脚本是一个完整的文件,特别是有API类型的时候,比如有类似于JAVA的接口,面向对象设计时,通常使用GroovyClassLoader.
• ScriptEngine
  • JSR-223应该是推荐的一种使用策略.规范化,而且简便.

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ScriptEngine

• pom.xml依赖

<dependency>
    <groupId>org.codehaus.groovy</groupId>
    <artifactId>groovy</artifactId>
    <version>2.1.6</version>
</dependency>
<dependency>
    <groupId>org.codehaus.groovy</groupId>
    <artifactId>groovy-jsr223</artifactId>
    <version>2.1.6</version>
</dependency>

• 代码样例

public static void evalScript() throws Exception{
    ScriptEngineManager factory = new ScriptEngineManager();
    //每次生成一个engine实例
    ScriptEngine engine = factory.getEngineByName("groovy");
    System.out.println(engine.toString());
    assert engine != null;
    //javax.script.Bindings
    Bindings binding = engine.createBindings();
    binding.put("date", new Date());
    //如果script文本来自文件,请首先获取文件内容
    engine.eval("def getTime(){return date.getTime();}",binding);
    engine.eval("def sayHello(name,age){return 'Hello,I am ' + name + ',age' + age;}");
    Long time = (Long)((Invocable)engine).invokeFunction("getTime", null);
    System.out.println(time);
    String message = (String)((Invocable)engine).invokeFunction("sayHello", "zhangsan",new Integer(12));
    System.out.println(message);
}

• 实际案例，Java调用groovy文件里面的方法，并传递参数

static void simpleTest() throws IOException, InstantiationException, IllegalAccessException, ResourceException, ScriptException{
    String[] roots = new String[] { "src/main/groovy/com/mobile263/billing/groovy/" };
    //通过指定的roots来初始化GroovyScriptEngine
    GroovyScriptEngine gse = new GroovyScriptEngine(roots);
    GroovyObject groovyObject = (GroovyObject) gse.loadScriptByName("TestScript.groovy").newInstance();
    String result = (String) groovyObject.invokeMethod("output", "hello");
    System.out.println(result);
}
class TestScript {
    static String output(def str){
        println str;
        return "hello"+str;
    }
}

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传送门

Groovy入门

Groovy入门

与java的异同

与java的异同

Java嵌入Groovy

Java嵌入Groovy

数据库

import groovy.sql.Sql;
import org.h2.tools.Server; 

    def db = Sql.newInstance('jdbc:mysql://10.200.1.6:3306/test', 'root', 'aaaaaa', 'com.mysql.jdbc.Driver');

    db.execute(''' CREATE TABLE leike(mac varchar(20) NOT NULL PRIMARY KEY)''');

    def macs = new File('shroute_inst.csv').readLines() 
    //重复的mac地址个数: 也就是这么多地址更换了平台.
    macs.each{
        db.execute('INSERT INTO t1(c) values(?)', [it]);
    }