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将jar文件输出字节流

使用fat jar  将一个工程打包后,使用以下代码 将jar输出为字节流

    public final static byte[] findJarBytes(String path){        File file = new File(path);        try{            FileInputStream fis = new FileInputStream(file);            JarInputStream jis = new JarInputStream(fis);            Manifest manifest = jis.getManifest();            ByteArrayOutputStream out = new ByteArrayOutputStream();            JarOutputStream jos = null;            if(manifest!=null)                jos = new JarOutputStream(out,jis.getManifest());            else jos = new JarOutputStream(out);                        JarEntry e = null;while ((e=jis.getNextJarEntry()) != null){                System.out.println(e.getName());                jos.putNextEntry(e);            }            jos.finish();            jos.close();            out.close();            jis.close();            fis.close();            return out.toByteArray();        }catch(Exception e){            e.printStackTrace();        }        return null;    }

经测试成功输出

使用ant 打包成jar包,使用同样的代码却发现抛出

java.util.zip.ZipException: invalid entry size (expected 5103 but got 0 bytes)    at java.util.zip.ZipOutputStream.closeEntry(ZipOutputStream.java:243)    at java.util.zip.ZipOutputStream.putNextEntry(ZipOutputStream.java:177)    at java.util.jar.JarOutputStream.putNextEntry(JarOutputStream.java:109)    at com.meteorite.holy.verify.util.JarUtil.findJarBytes(JarUtil.java:136)

比较两个jar包后,发现只有MANIFEST.MF文件不一致,替换成之前成功的,发现同样报错,至今不解,大致估计是fat jar 和 ant jar 生成方式不同

折腾了一会,将代码中间的替换成

            byte[] bytes = new byte[1024];            while ((e=jis.getNextJarEntry()) != null){                System.out.println(e.getName());                jos.putNextEntry(e);                int len = 0;                while((len = jis.read(bytes, 0, bytes.length))!=-1){                    jos.write(bytes, 0, len);                }            }        

经测试成功!