在javac中使用Runtime#exec()-无类文件
下面的在javac中使用Runtime#exec()-无类文件,java,runtime,Java,Runtime,下面的MyCompilingUtility.java通过PrintWriter创建一个文件(一个java类-AutoGenerated.java)。此类只有一个带有print语句的Main方法。其次,该程序调用javac AutoGenerated.java public static void main(String args[]) throws IOException, FileNotFoundException, UnsupportedEncodingException {
MyCompilingUtility.java
通过PrintWriter
创建一个文件(一个java类-AutoGenerated.java
)。此类只有一个带有print语句的Main方法。其次,该程序调用javac AutoGenerated.java
public static void main(String args[]) throws IOException,
FileNotFoundException, UnsupportedEncodingException {
createFile("AutoGenerated.java");
compile("AutoGenerated.java");
}
public static void compile(String fileName) throws IOException {
final String javacPath = "C:/Program Files/Java/jdk1.7.0_51/bin/javac.exe";
Runtime rt = Runtime.getRuntime();
final String compileCmd = javacPath + " " + fileName;
rt.exec(compileCmd);
}
public static void createFile(String fileName) throws FileNotFoundException,
UnsupportedEncodingException {
PrintWriter writer = new PrintWriter(fileName, "UTF-8");
writer.println("public class AutoGenerated");
writer.println("{");
writer.println(" public static void main(String [] args)");
writer.println(" {");
writer.println(" System.out.println(\"Hello from AutoGenerated World\")");
writer.println(" }");
writer.println("}");
writer.close();
}
但是,在运行javac MyCompilingUtility.java&&java MyCompilingUtility
之后,没有生成任何AutoGenerated.class
文件
为什么会这样?您缺少一个
代码>在
writer.println(" System.out.println(\"Hello from AutoGenerated World\");");
^
编译器根本无法编译它。从exec()
获取进程
,并调用其waitFor
方法。它返回了什么代码?我应该读文件的@索蒂里奥斯德里曼努利斯。运行waitFor
返回1。这些文档()说0
表示正常完成。@KevinMeredith为了以后的参考,复制的步骤是:运行代码,修改代码以添加对退出代码的检查,读取错误InputStream
(Process#getErrorStream()
),它准确地说明了问题。