import java.io.File;

/**
 * new File("..\path\abc.txt") 中的三個方法獲取路徑的方法 <br>
 * 1： getPath() 獲取相對路徑，例如 ..\path\abc.txt <br>
 * 2： getAbslutlyPath() 獲取絕對路徑，但可能包含 ".." 或 "." 字符，例如D:\otherPath\..\path\abc.txt <br>
 * 3： getCanonicalPath() 獲取絕對路徑，但不包含 ".." 或 "." 字符，例如 D:\path\abc.txt
 
 
*/
public class PathUtil {

    private static String webRootPath;
    private static String rootClassPath;

    @SuppressWarnings("rawtypes")
    public static String getPath(Class clazz) {
        String path = clazz.getResource("").getPath();
        return new File(path).getAbsolutePath();
    }

    
 
public static String getPath(Object object) {
        String path = object.getClass().getResource("").getPath();
        return new File(path).getAbsolutePath();
    }

    public static String getRootClassPath() {
        if (rootClassPath == null) {
            try {
                String path = PathUtil.class
 
.getClassLoader().getResource("").toURI().getPath();
                rootClassPath = new File(path).getAbsolutePath();
            } catch (Exception e) {
                String path = PathUtil.class.getClassLoader().getResource("").getPath();
                rootClassPath = new File(path).getAbsolutePath();
            }
        }
        return rootClassPath;
    }

    public static String getPackagePath(Object object) {
        Package p = object.getClass().getPackage();
        return p != null ? p.getName().replaceAll("\\.", "/") : "";
    }

    public static File getFileFromJar(String file) {
        throw new RuntimeException("Not finish. Do not use this method.");
    }

    public static String getWebRootPath() {
        if (webRootPath == null)
            webRootPath = detectWebRootPath();
        return webRootPath;
    }

    public static void setWebRootPath(String webRootPath) {
        if (webRootPath == null)
            return;
        if (webRootPath.endsWith(File.separator))
            webRootPath = webRootPath.substring(0, webRootPath.length() - 1);
        PathUtil.webRootPath = webRootPath;
    }

    private static String detectWebRootPath() {
        try {
            String path = PathUtil.class.getResource("/").toURI().getPath();
            return new File(path).getParentFile().getParentFile().getCanonicalPath();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

java獲取項目路徑