java 通过指定url地址下载文件到本地工具类(包含https的数字签名请求)

待我称王封你为后i 2024-02-19 09:25 40阅读 0赞

##### java 通过指定url地址下载文件到本地工具类(包含https的数字签名请求) #####

###### XFileUtils ######

public class XFileUtils {
        
    
        /**
         * 从网络Url中下载文件
         * @param urlStr url的路径
         * @throws IOException
         */
        public static String  downLoadByUrl(String urlStr,String savePath, String fileName) {
        
            if (StrUtil.isBlank(fileName)) {
        
                fileName = getFileName(urlStr);
            }
            InputStream inputStream = null;
            FileOutputStream fos = null;
            try {
        
                URL url = new URL(urlStr);
                // 防止https被证书校验报错，信任所有证书
                if(urlStr.contains("https")){
        
                    SslUtils.ignoreSsl();
                }
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                //设置超时间为10秒
                conn.setConnectTimeout(10 * 1000);
                //得到输入流
                inputStream = conn.getInputStream();
                //获取自己数组
                byte[] getData = readInputStream(inputStream);
                //文件保存位置
                File saveDir = new File(savePath);
                if (!saveDir.exists()) {
         // 没有就创建该文件
                    saveDir.mkdir();
                }
                File file = new File(saveDir + File.separator + fileName);
                fos = new FileOutputStream(file);
                fos.write(getData);
    
            } catch (Exception e) {
        
                e.printStackTrace();
            } finally {
        
                IoUtil.close(fos);
                IoUtil.close(inputStream);
            }
            return fileName;
        }
    
        /**
         * 从输入流中获取字节数组
         * @param inputStream
         * @return
         * @throws IOException
         */
        private static  byte[] readInputStream(InputStream inputStream) throws IOException {
        
            byte[] buffer = new byte[4*1024];
            int len = 0;
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            while((len = inputStream.read(buffer)) != -1) {
        
                bos.write(buffer, 0, len);
            }
            bos.close();
            return bos.toByteArray();
        }
    
        /**
         * 从src文件路径获取文件名
         * @param srcRealPath src文件路径
         * @return 文件名
         */
        private static String getFileName(String srcRealPath){
        
            return StringUtils.substringAfterLast(srcRealPath,"/");
        }
    }

测试类：

public static void main(String[] args) {
        
            String url = "https://xxxxxxxxxxxx/kpfw/fpjfzz/v1/exportDzfpwjEwm?Wjgs=PDF&Jym=7D1E&Fphm=23512000000118158368&Czsj=1699335192593&Kprq=20231107111703";
    //        String url = "https://www.w3school.com.cn/example/xmle/note.xml";
            String filePath = "D:\\workFile";
    
            String fileName = XFileUtils.downLoadByUrl(url, filePath, null);
        }

javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    	at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
    	at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:371)
    	at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:314)
    	at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:309)
    	at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:654)
    	at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(CertificateMessage.java:473)
    	at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(CertificateMessage.java:369)
    	at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:396)
    	at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:480)
    	at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:458)
    	at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:201)
    	at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:172)
    	at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1505)
    	at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1420)
    	at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:455)
    	at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:426)
    	at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:578)
    	at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:183)
    	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1665)
    	at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1589)
    	at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:224)
    	at example.common.utils.XFileUtils.downLoadByUrl(XFileUtils.java:36)
    	at example.common.utils.XFileUtils.main(XFileUtils.java:89)

> 由上面的测试类，可以发现，http请求是可以正常下载文件到本地，但是如果是https，就会报错。这是因为java对SSL证书不信任造成，需要证书鉴权。这种报错有两种比较常用的解决方式。

##### 解决java对SSL证书不信任造成报错（https） #####

###### 一、运行或者打包去掉SSL证书检验（不推荐） ######

> \-Dmaven.wagon.http.ssl.insecure=true -Dmaven.wagon.http.ssl.allowall=true

###### 二、导入证书（不推荐） ######

###### 三、信任所有SSL证书(推荐) ######

public class SslUtils {
        
    
        private static final Logger logger = LoggerFactory.getLogger(SslUtils.class);
        private static void trustAllHttpsCertificates() throws Exception {
        
            TrustManager[] trustAllCerts = new TrustManager[1];
            TrustManager tm = new miTM();
            trustAllCerts[0] = tm;
            SSLContext sc = SSLContext.getInstance("SSL");
            sc.init(null, trustAllCerts, null);
            HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
        }
        static class miTM implements TrustManager, X509TrustManager {
        
            public X509Certificate[] getAcceptedIssuers() {
        
                return null;
            }
            public boolean isServerTrusted(X509Certificate[] certs) {
        
                return true;
            }
            public boolean isClientTrusted(X509Certificate[] certs) {
        
                return true;
            }
            public void checkServerTrusted(X509Certificate[] certs, String authType)
                    throws CertificateException {
        
                return;
            }
            public void checkClientTrusted(X509Certificate[] certs, String authType)
                    throws CertificateException {
        
                return;
            }
        }
        /**
         * 忽略HTTPS请求的SSL证书，必须在openConnection之前调用
         * @throws Exception
         */
        public static void ignoreSsl() throws Exception{
        
            HostnameVerifier hv = new HostnameVerifier() {
        
                public boolean verify(String urlHostName, SSLSession session) {
        
                    logger.info("Warning: URL Host: " + urlHostName + " vs. " + session.getPeerHost());
                    return true;
                }
            };
            trustAllHttpsCertificates();
            HttpsURLConnection.setDefaultHostnameVerifier(hv);
        }
    }

> **PS：必须在openConnection之前调用，SslUtils.ignoreSsl();**

> 至此，通过上面的工具类就解决证书不信任，可以通过url地址下载正常下载文件