Use try-with-resources or close this “FileInputStream” in a “finally” clause.

使用sonarqube检查代码时报错
Use try-with-resources or close this “FileInputStream” in a “finally” clause.
原始代码是这样的，当时是个阻断的bug

    private static void copyFile(String copyFile, String newFile) throws Exception {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            fis = new FileInputStream(copyFile);
            fos = new FileOutputStream(newFile, true);
            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fis.read(bytes)) != -1) {
                fos.write(bytes, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                fos.close();
            }
            if (fis != null) {
                fis.close();
            }
        }
    }

三种种解决方案
1.finally里close的时候用try{}catch{}包起来就好了

private static void copyFile(String copyFile, String newFile) throws Exception {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        try {
            fis = new FileInputStream(copyFile);
            fos = new FileOutputStream(newFile, true);
            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = fis.read(bytes)) != -1) {
                fos.write(bytes, 0, len);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

2.类实现AutoCloseable方法也可以，直接不用写finally就可以

public class AutoCloseableDemo {
    public static void main(String[] args) {
        try (AutoCloseableObjecct app = new AutoCloseableObjecct()) {
            System.out.println("--执行main方法--");
        } catch (Exception e) {
            System.out.println("--exception--");
        } finally {
            System.out.println("--finally--");
        }
    }

    //自己定义类 并实现AutoCloseable
    public static class AutoCloseableObjecct implements AutoCloseable {
        @Override
        public void close() throws Exception {
            System.out.println("--close--");
        }

    }


    @Test
    public void demo2() {

        //JDK1.7之前,释放资源方式
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream("");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        //1.7之后，只要实现了AutoCloseable接口
        try (FileInputStream fileInputStream2 = new FileInputStream("")) {

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

3.直接用try包起来，java8之后try包起来的会自动关闭流

try (ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream("file.txt"))) {
    // Write to the ObjectOutputStream here
} catch (IOException e) {
    e.printStackTrace();
}