/** * 動態執行一段代碼(生成文件->編譯->執行) * @author kingfish * @version 1.0 */ public class TestRun { PRivate String fileName = "Test.java"; private String className= "Test.class"; public TestRun() { File f = new File(fileName); if(f.exists()) f.delete();
f = new File(className); if(f.exists()) f.delete(); }
/** * 創建java文件 */ public void createJavaFile(String body) { String head = "public class Test{/r/n public static void runCode(){";
String end = "/r/n }/r/n}"; try { DataOutputStream dos = new DataOutputStream(new FileOutputStream( fileName)); dos.writeBytes(head); dos.writeBytes(body); dos.writeBytes(end); dos.close(); } catch (Exception e) { e.printStackTrace(); } }
/** * 編譯 */ public int makeJavaFile() { int ret = 0; try { Runtime rt = Runtime.getRuntime(); Process ps = rt.exec("cmd /c javac " + fileName); ps.waitFor(); byte[] out = new byte[1024]; DataInputStream dos = new DataInputStream(ps.getInputStream()); dos.read(out); String s = new String(out); if (s.indexOf("Exception") > 0) { ret = -1; } } catch (Exception e) { ret = -1; e.printStackTrace(); } return ret; }
/** * 反射執行 */ public void run() { try { Class.forName("Test").getMethod("runCode", new Class[] {}).invoke(null, new Object[]{}); } catch (Exception e) { e.printStackTrace(); } }
/** * 測試 */ public static void main(String[] args) {
String cmd = "System.out.println(/"usage:java TestRun int i=1; System.out.println(i+100);/");"; if(args.length>=1){ cmd = args[0]; } TestRun t = new TestRun(); t.createJavaFile(cmd); if (t.makeJavaFile() == 0) { t.run(); } } }
