Java中的语法检查

Question

我目前正在开发一个具有嵌入式文本编辑器的程序.用户应该在编辑器中键入java代码.然后将编入编辑器的代码转换为字符串.我只想要一些能够检查缺失括号或没有捕获的尝试等等.它不需要编译.我已经看了很多,但我仍然是编程的新手,无法实现一些更难的东西.

所以要缩短它:我正在寻找一些可以分析代码的语法错误的java包.

Answer 1

从Java 6开始,您可以使用JavaCompiler编译文本并获取诊断对象,以告诉您文件有什么问题(如果有的话).因此,对于您的示例,您需要获取编辑器的内容并将其传递给JavaCompiler,运行它,并报告任何问题.下面的示例假定编辑器文本写出文件.

示例代码:

要检查的文件

public class HelloBuggyWorld {
    String test // missing a semicolon

    public static void main (String [] args) {
        System.out.println('Hello World!');  // should be double quoted
    }
}

检查

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Formatter;
import java.util.List;
import java.util.Locale;

import javax.tools.Diagnostic;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

public class JavaSyntaxChecker {
    public static void main(String[] args) {
        System.out.println(JavaSyntaxChecker.check("/path/to/HelloBuggyWorld.java"));
    }

    public static List<String> check(String file) {
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
        Iterable<? extends JavaFileObject> compilationUnits =
                fileManager.getJavaFileObjectsFromStrings(Arrays.asList(file));

        DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();
        compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnits).call();

        List<String> messages = new ArrayList<String>();
        Formatter formatter = new Formatter();
        for (Diagnostic diagnostic : diagnostics.getDiagnostics()) {
            messages.add(diagnostic.getKind() + ":\t Line [" + diagnostic.getLineNumber() + "] \t Position [" + diagnostic.getPosition() + "]\t" + diagnostic.getMessage(Locale.ROOT) + "\n");
        }

        return messages;
    }
}

产量

从运行main方法.

[ERROR:  Line [5]    Position [124] HelloBuggyWorld.java:5: unclosed character literal
, ERROR:     Line [5]    Position [126] HelloBuggyWorld.java:5: ';' expected
, ERROR:     Line [5]    Position [131] HelloBuggyWorld.java:5: not a statement
, ERROR:     Line [5]    Position [136] HelloBuggyWorld.java:5: ';' expected
, ERROR:     Line [5]    Position [137] HelloBuggyWorld.java:5: unclosed character literal
]