JavaFormatter

在修改Hibernate Tools的源码的时候,发现的一个java格式化工具类.

package org.hibernate.tool.ide.formatting;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.ToolFactory;
import org.eclipse.jdt.core.formatter.CodeFormatter;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.text.edits.TextEdit;
import org.hibernate.tool.hbm2x.ExporterException;


public class JavaFormatter {

	private CodeFormatter codeFormatter;

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		//DefaultCodeFormatter.USE_NEW_FORMATTER = true;
		HashMap hashMap = new HashMap();
		hashMap.put(JavaCore.COMPILER_SOURCE, "1.5");
		hashMap.put(JavaCore.COMPILER_COMPLIANCE, "1.5");
		hashMap.put(JavaCore.COMPILER_CODEGEN_TARGET_PLATFORM, "1.5");
		final CodeFormatter codeFormatter = ToolFactory.createCodeFormatter(hashMap);
		
		JavaFormatter format = new JavaFormatter(null);
		format.formatFile(new File("D:\\workspace\\CodeGenerator\\src\\com\\Table3.java"));

	}
	
	public JavaFormatter(Map settings) {
		if(settings==null) {
			// if no settings run with jdk 5 as default 
			settings = new HashMap();
			settings.put( JavaCore.COMPILER_SOURCE, "1.5");
			settings.put( JavaCore.COMPILER_COMPLIANCE, "1.5");
			settings.put( JavaCore.COMPILER_CODEGEN_TARGET_PLATFORM, "1.5");			
		}
		
		this.codeFormatter = ToolFactory.createCodeFormatter(settings);
	}

	/**
	 * Throws exception if not possible to read or write the file.
	 * Returns true if formatting went ok; returns false if the formatting could not finish because of errors in the input.
	 *  
	 * @param file
	 * @param codeFormatter
	 * @return
	 */
	public boolean formatFile(File file) throws ExporterException {
		IDocument doc = new Document();
		try {
			String contents = new String(org.eclipse.jdt.internal.compiler.util.Util.getFileCharContent(file, null));
			doc.set(contents);
			TextEdit edit = codeFormatter.format(CodeFormatter.K_COMPILATION_UNIT, contents, 0, contents.length(), 0, null);
			if (edit != null) {
				edit.apply(doc);
			} else {				
				return false; // most likely syntax errror
			}

			// write the file
			final BufferedWriter out = new BufferedWriter(new FileWriter(file));
			try {
				out.write(doc.get());
				out.flush();
			} finally {
				try {
					out.close();
				} catch (IOException e) {
					/* ignore */
				}
			}
			return true;
		} catch (IOException e) {
			throw new ExporterException("Could not format " + file, e);
		} catch (BadLocationException e) {			
			throw new ExporterException("Could not format " + file, e);
		}
	}

}