myeclipse转eclipse jee的工程文件补丁（主要是maven补丁）

以下是用来将myeclipse（或者其他没有加maven配置的工程）的工程文件装换到最新的m2eclipse插件所能识别的格式，

简单来说就是修改.project和.classpath

使用方法：

1. 在workspace任意层级下（当然啦，这个workspace的名字要包含" workspace"字样），运行: java  EclipseM2Patch

2. 在任意目录下指定workspace目录，运行: java  EclipseM2Patch /java/workspace

运行后将会对workspace下的所有需要patch工程文件进行patch，如果不满意还可以回滚，满意就删除所有备份文件。

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

public class EclipseM2Patch {

	private static String fileToString(File f) throws Exception {
		byte[] bytes = fileToBytes(f);
		if (bytes.length == 0)
			return null;
		return new String(bytes, "iso-8859-1");
	}

	private static byte[] fileToBytes(File f) throws Exception {
		if (!f.exists())
			return null;
		FileInputStream fis = null;
		byte[] all = new byte[0];
		try {
			byte[] buf = new byte[1024];
			fis = new FileInputStream(f);
			int read = -1;
			while ((read = fis.read(buf)) != -1) {
				byte[] tmp = new byte[all.length + read];
				if (all.length > 0)
					System.arraycopy(all, 0, tmp, 0, all.length);
				System.arraycopy(buf, 0, tmp, all.length, read);
				all = tmp;
			}
		} finally {
			if (fis != null)
				fis.close();
		}
		return all;
	}

	private static void write(File f, String content) throws Exception {
		FileOutputStream fos = new FileOutputStream(f);
		try {
			fos.write(content.getBytes("iso-8859-1"));
		} finally {
			fos.close();
		}
	}

	private static File backup(File f) throws Exception {
		byte[] bytes = fileToBytes(f);
		if (bytes.length > 0) {
			File backupfile = new File(f.getAbsoluteFile() + ".patchbackup");
			FileOutputStream fos = new FileOutputStream(backupfile);
			try {
				fos.write(bytes);
			} finally {
				fos.close();
			}
			return backupfile;
		}
		return null;
	}

	public static void main(String[] args) throws Exception {
		String workspacepath = args.length == 0 ? null : args[0];
		if (workspacepath == null) {
			File file = new File(".");
			String p = file.getAbsolutePath().replaceAll("(?i)(workspace[^\\\\/]+).*", "$1");
			if (p.length() != file.getAbsolutePath().length()) {
				workspacepath = p;
			}
		}
		if (workspacepath == null) {
			throw new IllegalAccessException();
		}
		ArrayList<File> backups = new ArrayList<File>();
		File workspace = new File(workspacepath);
		for (File projectBaseDir : workspace.listFiles()) {
			if (projectBaseDir.isDirectory()
					&& projectBaseDir.getName().matches("^\\p{Alpha}[\\p{Alpha}_-]+$")) {
				File _project = new File(projectBaseDir, ".project");
				File _classpath = new File(projectBaseDir, ".classpath");
				if (_project.exists()) {
					String content = fileToString(_project);
					String addToContent = "<nature>org.eclipse.m2e.core.maven2Nature</nature>";
					if (!content.contains(addToContent)) {
						File backupfile = backup(_project);
						if (backupfile != null)
							backups.add(backupfile);
						content = content.replaceAll("(?im)(\\s+)(?=</natures>)", "$1\t" + addToContent
								+ "$1");
						write(_project, content);
						System.out.println("file:" + _project + " - patched");
					} else {
						File backupfile = new File(_project.getAbsoluteFile() + ".patchbackup");
						if (backupfile.exists()) {
							backups.add(backupfile);
						}
					}
				}
				if (_classpath.exists()) {
					String content = fileToString(_classpath);
					String addToContent = "<classpathentry kind=\"con\" path=\"org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER\"/>";
					if (!content.contains("org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER")) {
						File backupfile = backup(_classpath);
						if (backupfile != null)
							backups.add(backupfile);
						content = content.replaceAll("(?im)(\\s+)(?=</classpath>)", "$1\t" + addToContent
								+ "$1");
						write(_classpath, content);
						System.out.println("file:" + _classpath + " - patched");
					} else {
						File backupfile = new File(_classpath.getAbsoluteFile() + ".patchbackup");
						if (backupfile.exists()) {
							backups.add(backupfile);
						}
					}
				}
			}
		}
		BufferedReader rd = new BufferedReader(new InputStreamReader(System.in));
		String line = null;
		if (backups.size() > 0) {
			System.out.println(">Delete all backups?(Y-yes/N-no/R-rollback)");
			line = rd.readLine();
			for (File f : backups) {
				if ("y".equalsIgnoreCase(line)) {
					boolean delete = f.delete();
					System.out.println("Delete file:" + f + " - " + (delete ? "ok" : "fail"));
				} else if ("r".equalsIgnoreCase(line)) {
					File file = new File(f.getAbsolutePath().replace(".patchbackup", ""));
					boolean result = file.delete();
					if (result)
						result = f.renameTo(file);
					System.out.println("Rollback file:" + f + " - " + (result ? "ok" : "fail"));
				}
			}
		}
		System.out.println(">Press any key to continue...");
		line = rd.readLine();
		rd.close();
	}
}