動態編譯

?

?下面的demo就涵蓋了動態編譯和運行類的過程

package 動態編譯;

import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;

public class Demo {

public static void main(String[] args) throws Exception {
JavaCompiler compiler=ToolProvider.getSystemJavaCompiler();

int result=( compiler.run(null,null, null,"G:/test.java"));
System.out.println(result==0?"編譯成功":"編譯失敗");
// //1：通過runtime.getRuntime運行啟動好的進程運行
// Runtime run=Runtime.getRuntime();
// Process process =run.exec("java -cp c:/myjava HelloWorld");
// InputStream io=process.getInputStream();
// BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(io));
// String info="";
// while((info= bufferedReader.readLine())!=null) {
// System.out.println(info);
// }
//2通過反射運行編譯的類‘
URL [] urls=new URL[] {new URL("file:/"+"C:/myjava/")};
URLClassLoader classLoader=new URLClassLoader(urls);
Class c=classLoader.loadClass("test");
Method c1= c.getMethod("main", String[].class);
c1.invoke(null, (Object)new String[] {"aa","bb"});
//注意要加Object,否則會理解為傳入aa,bb兩個參數了，而不是一個數組
}
}