后端发送HTTP请求
1 原始方式
背景：
get：获取微信的accessToken
post：设置微信公众号的自定义菜单
1.1 get方式
//get方式发起请求
public String get(String url){
try{
URL urlObj = new URL(url);
//开连接
URLConnection connection = urlObj.openConnection();
InputStream is = connection.getInputStream();
byte[] b = new byte[1024];
int len;
StringBuilder stb = new StringBuilder();
while((len=is.read(b)) != -1){
stb.append(new String(b, 0, len));
}
return stb.toString();
} catch (Exception e){
e.printStackTrace();
}
return null;
}
1.2 post方式
//post方式发起请求，data是请求体
public static String post(String url, String data){
try{
URL urlObj = new URL(url);
URLConnection connection = urlObj.openConnection();
//要发送数据出去，必须要设置为可发送数据状态
connection.setDoOutput(true);
//获取输出流
OutputStream os = connection.getOutputStream();
//写出数据
os.write(data.getBytes());
os.close();
//获取输入流
InputStream is = connection.getInputStream();
byte[] b = new byte[1024];
int len;
StringBuilder stb = new StringBuilder();
while((len = is.read(b)) != -1){
stb.append(new String(b, 0, len));
}
return stb.toString();
} catch (Exception e){
e.printStackTrace();
}
return null;
}
2 使用OKHttp
导入依赖：
<dependency>
<groupId>com.squareup.okhttp3</groupId>
<artifactId>okhttp</artifactId>
<version>3.8.0</version>
</dependency>
2.1 基本方式
①通过get方式
public void OkHttpGet(String url) {
OkHttpClient okHttpClient = new OkHttpClient();
//不配url方法会报错，肯定要有访问地址的嘛
//.Builder是Request内部类 .url()返回Builder .build()返回Request对象
Request request = new Request.Builder()
//.addHeader("a", "b")//.addHeader添加键值对header信息
//.get()//可加可不加
.url(url)
.build();
Call call = okHttpClient.newCall(request);
try {
Response response = call.execute();
System.out.println(response.body().string());
//http状态码
System.out.println(response.code());
//response的头信息
System.out.println(response.headers().toString());
//请求响应时间，收到时间减去发送的时间，单位毫秒
System.out.println(response.receivedResponseAtMillis()-response.sentRequestAtMillis());
} catch (IOException e) {
e.printStackTrace();
}
}
②通过post方式
public void OkHttpPost(String url){
//ssl认证重写
OkHttpClient okHttpClient=new OkHttpClient.Builder().hostnameVerifier(
new HostnameVerifier() {
@Override
public boolean verify(String s, SSLSession sslSession) {
return true;
}
}
).build();
RequestBody requestBody=new FormBody.Builder()
.add("oldPassword","111111")
.add("newPassword","111111")
.build();
Request request=new Request.Builder()
.url(url)
.post(requestBody)
.addHeader("Cookie","JSESSIONID=299571E0E40DA6E9962E41B87A669BBB")
.addHeader("content-type", "application/json")
.addHeader("cache-control", "no-cache")
.build();
Call call=okHttpClient.newCall(request);
try {
Response response=call.execute();
System.out.println(response.body().string());
} catch (IOException e) {
e.printStackTrace();
}
}
2.2 封装OKHttp
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import okhttp3.*;
import okio.BufferedSink;
import okio.Okio;
import java.io.File;
import java.util.HashMap;
import java.util.Map;
@Slf4j
public class OkHttpUtil {
/**
* Get请求
* @param url URL地址
* @return 返回结果
*/
public static String get(String url){
String result=null;
try {
OkHttpClient okHttpClient=new OkHttpClient();
Request request = new Request.Builder().url(url).build();
Response response = okHttpClient.newCall(request).execute();
result=response.body().string();
log.info("Get请求返回：{}",result);
return result;
}catch (Exception e){
log.error("OkHttp[Get]请求异常",e);
return result;
}
}
/**
* Post请求
* @param url URL地址
* @param params 参数
* @return 返回结果
*/
public static String post(String url,Map<String,String> params){
String result=null;
if (params==null){
params=new HashMap<String, String>();
}
try {
OkHttpClient okHttpClient=new OkHttpClient();
FormBody.Builder formBodyBuilder = new FormBody.Builder();
//添加参数
log.info("params：{}", JSON.toJSONString(params));
for (Map.Entry<String,String> map:params.entrySet()){
String key=map.getKey();
String value;
if (map.getValue()==null){
value="";
}else{
value=map.getValue();
}
formBodyBuilder.add(key,value);
}
FormBody formBody =formBodyBuilder.build();
Request request = new Request.Builder().url(url).post(formBody).build();
Response response = okHttpClient.newCall(request).execute();
result=response.body().string();
log.info("Post请求返回：{}",result);
return result;
}catch (Exception e){
log.error("OkHttp[Post]请求异常",e);
return result;
}
}
/**
* 上传文件请求（Post请求）
* @param url URL地址
* @param params 文件 key：参数名 value：文件 （可以多文件）
* @return 返回结果
*/
public static String upload(String url, Map<String, File> params){
String result=null;
try {
OkHttpClient okHttpClient=new OkHttpClient();
MultipartBody.Builder multipartBodyBuilder =new MultipartBody.Builder().setType(MultipartBody.FORM);
for (Map.Entry<String,File> map:params.entrySet()){
String key=map.getKey();
File file=map.getValue();
if (file==null||(file.exists() && file.length() == 0)){
continue;
}
multipartBodyBuilder.addFormDataPart(key,file.getName(),RequestBody.create(MediaType.parse("multipart/form-data"), file));
}
RequestBody requestBody =multipartBodyBuilder.build();
Request request = new Request.Builder().url(url).post(requestBody).build();
Response response = okHttpClient.newCall(request).execute();
result=response.body().string();
log.info("Upload请求返回：{}",result);
return result;
}catch (Exception e){
log.error("OkHttp[Upload]请求异常",e);
return result;
}
}
/**
* 下载文件请求（Get请求）
* @param url URL地址
* @param savePath 保存路径（包括文件名）
* @return 文件保存路径
*/
public static String download(String url,String savePath){
String result=null;
try {
OkHttpClient okHttpClient=new OkHttpClient();
Request request = new Request.Builder().url(url).build();
Response response = okHttpClient.newCall(request).execute();
File file=new File(savePath);
if (!file.getParentFile().exists()){
file.getParentFile().mkdirs();
}
BufferedSink sink =Okio.buffer((Okio.sink(file)));
sink.writeAll(response.body().source());
sink.flush();
sink.close();
result=savePath;
log.info("Download请求返回：{}",result);
return result;
}catch (Exception e){
log.error("OkHttp[Download]请求异常",e);
return result;
}
}
}
2.3 OKHttp的post方式详解
①基本的post请求，包含参数
/**
* post请求的body中带有参数
*/
@Test
public void postWithBody() throws IOException {
//构建请求的body
RequestBody body = new FormBody.Builder()
.add("username", "zhangsan")
.add("password", "123456")
.build();
//构建请求
Request request = new Request.Builder()
.url(base_url + "testOkHttpByPost")
.post(body)
.build();
Call call = client.newCall(request);
Response response = call.execute();
Assert.assertEquals(response.code(), 200);
}
//post请求的body中带有参数
@PostMapping("/testOkHttpByPost")
public void testOkHttpByPost(HttpServletRequest request) {
Map<String, String[]> parameterMap = request.getParameterMap();
for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
System.out.println(entry.getKey());
String[] value = entry.getValue();
System.out.println(Arrays.toString(value));
}
}
②post请求带有授权
/**
* post请求带有授权的
*/
@Test
public void postWithAuth() throws IOException {
String postBody = "test post auth";
Request request = new Request.Builder()
.url(base_url + "testOkHttpByAuth")
.addHeader("Authorization", "Messi")
.post(RequestBody.create(
MediaType.parse("text/x-markdown"), postBody))
.build();
Call call = client.newCall(request);
Response response = call.execute();
Assert.assertEquals(response.code(), 200);
}
//post请求中带有身份验证
@PostMapping("/testOkHttpByAuth")
public void testOkHttpByAuth(HttpServletRequest request, @RequestBody String text){
String authorization = request.getHeader("Authorization");
if("Messi".equals(authorization)){
System.out.println("success...");
}else {
System.out.println("fail....");
}
System.out.println(text);//test post auth
}
③post请求中带有json数据
/**
* post向请求体中发送json数据
*/
@Test
public void postByJson() throws IOException {
String json = "{\n" +
" \"username\":\"laowang\",\n" +
" \"age\":18\n" +
"}";
//为了在请求体中发送json，需要设置媒体类型为application/json
RequestBody body = RequestBody.create(
MediaType.parse("application/json"),json);
Request request = new Request.Builder()
.url(base_url + "/postByJson")
.post(body)
.build();
Call call = client.newCall(request);
Response response = call.execute();
Assert.assertEquals(response.code(), 200);
}
//post请求体带有json数据
@PostMapping("/postByJson")
public void testOkHttpByJson(@RequestBody String json){
System.out.println(json);
}
④发送Multipart post
/**
* 发送 Multipart post请求
*/
@Test
public void postByMultipart() throws IOException {
RequestBody body = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("username", "wangchen")
.addFormDataPart("password", "123456")
.addFormDataPart("file", "file.txt",
RequestBody.create(MediaType.parse("application/octet-stream"),
new File("src/main/resources/text.txt")))
.build();
Request request = new Request.Builder()
.url(base_url + "/postMultipart")
.post(body)
.build();
Call call = client.newCall(request);
Response response = call.execute();
Assert.assertEquals(response.code(), 200);
}
//发送Multipart post
@PostMapping("/postMultipart")
public void testOkHttpMultipart(String username, String password, MultipartFile file){
System.out.println(username);
System.out.println(password);
String originalFilename = file.getOriginalFilename();
System.out.println(originalFilename);
}
⑤修改编码格式
//通过其他方式编码
//如果我们想使用其他字符编码，我们可以将其作为 MediaType.parse () 的第二个参数传入:
@Test
public void postByOtherEncoding(){
String json = "{\n" +
" \"username\":\"laowang\",\n" +
" \"age\":18\n" +
"}";
RequestBody body = RequestBody.create(
MediaType.parse("application/json;charset=UTF-8"), json);
String charset = body.contentType().charset().displayName();
Assert.assertEquals(charset, "UTF-16");
}
2.4 OKHttp发起同步异步请求
2.4.1 同步发送get请求
/**
* get请求【同步方式】
* @param url
* @return
*/
public static Response getWithNoParam(String url){
Response result = null;
try{
//设置5s超时
OkHttpClient client = new OkHttpClient.Builder().readTimeout(5, TimeUnit.SECONDS).build();
//请求
Request request = new Request.Builder().url(url).build();
System.out.println("request.headers() = " + request.headers().toString());
System.out.println(">>>>>>>>>>>" + request.headers().get("Host"));
//响应
Response response = client.newCall(request).execute();
//获取响应体内容
result = response;
return result;
} catch (Exception e){
log.error("get请求异常:{}", e);
return result;
}
}
/**
* 同步发送get请求【添加参数】
* @param url
* @param paramMap
* @return
*/
public static Response getWithParams(String url, Map<String, String> paramMap){
Request.Builder requestBuilder = new Request.Builder();
HttpUrl.Builder urlBuilder = HttpUrl.parse(url).newBuilder();
String key = "";
String value = "";
for(Map.Entry<String, String> entry : paramMap.entrySet()){
key = entry.getKey();
value = entry.getValue();
urlBuilder.addQueryParameter(key, value);
}
requestBuilder.url(urlBuilder.build());
Request request = requestBuilder.build();
OkHttpClient client = new OkHttpClient.Builder().readTimeout(5, TimeUnit.SECONDS).build();
Call call = client.newCall(request);
Response response = null;
try {
response = call.execute();
} catch (IOException e) {
e.printStackTrace();
}
return response;
}
2.4.2 异步发送get请求
/**
* 异步发起get请求
* @param url
*/
public static void getByAsync(String url){
OkHttpClient client = new OkHttpClient.Builder().readTimeout(5, TimeUnit.SECONDS).build();
Request request = new Request.Builder().url(url).get().build();
Call call = client.newCall(request);
call.enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
//请求失败之后所作操作...
System.out.println("fail.....");
}
@Override
public void onResponse(Call call, Response response) throws IOException {
//请求成功之后所做操作....异步请求成功之后的回调，例如：txtView.setText(response.body().string ());
System.out.println(response.body().string());
}
});
}
3 使用HttpClient
3.1 发送基本请求
//创建连接[同步连接]
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// CloseableHttpClient client = HttpClients.createDefault();//创建默认client【与上面没有区别】
//创建连接【异步】
CloseableHttpAsyncClient httpAsyncClient = HttpAsyncClientBuilder.create().build();
private String uri_prefix = "http://localhost:8080/";
①get方式
//get请求
@Test
public void testGet() throws IOException {
String url = uri_prefix + "testGet";
HttpGet httpGet = new HttpGet(url);
//给请求头设置值【get也可以通过拼接URL来传递参数】
httpGet.setHeader("token", "fadsofafa");
CloseableHttpResponse response = httpClient.execute(httpGet);
System.out.println(response.getEntity());
}
②put方式
//put请求
@Test
public void testPut() throws IOException {
String api = "testPut";
String url = uri_prefix + api;
HttpPut httpPut = new HttpPut(url);
//要传输的json数据【标准写法应该通过对象传输，然后转换为json串】
String json = "{\n" +
" \"username\":\"laowang\",\n" +
" \"age\":18\n" +
"}";
//传输json数据，修改request头信息
httpPut.setHeader("Content-Type", "application/json;charset=utf8");
//设置传输的json
httpPut.setEntity(new StringEntity(json, "UTF-8"));
CloseableHttpResponse response = httpClient.execute(httpPut);
System.out.println(EntityUtils.toString(response.getEntity()));
}
③post
//post请求[与put方式无太多区别]
@Test
public void testPost() throws IOException {
String api = "testPost";
String url = uri_prefix + api;
HttpPost httpPost = new HttpPost(url);
String json = "{\n" +
" \"username\":\"laowang\",\n" +
" \"age\":18\n" +
"}";
httpPost.setHeader("Content-Type", "application/json;charset=utf8");
//设置具体数据
httpPost.setEntity(new StringEntity(json, "UTF-8"));
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(response.getEntity());
}
④delete
//测试delete
@Test
public void testDelete() throws IOException {
String api = "testDelete";
String url = uri_prefix + api;
HttpDelete httpDelete = new HttpDelete(url);
CloseableHttpResponse response = httpClient.execute(httpDelete);
System.out.println(EntityUtils.toString(response.getEntity()));
}
其他同理
3.2 工具类HttpClientUtils
public class HttpClientUtils {
public static final int connTimeout=10000;
public static final int readTimeout=10000;
public static final String charset="UTF-8";
private static HttpClient client = null;
static {
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
cm.setMaxTotal(128);
cm.setDefaultMaxPerRoute(128);
client = HttpClients.custom().setConnectionManager(cm).build();
}
public static String postParameters(String url, String parameterStr) throws ConnectTimeoutException, SocketTimeoutException, Exception{
return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
}
public static String postParameters(String url, String parameterStr,String charset, Integer connTimeout, Integer readTimeout) throws ConnectTimeoutException, SocketTimeoutException, Exception{
return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
}
public static String postParameters(String url, Map<String, String> params) throws ConnectTimeoutException,
SocketTimeoutException, Exception {
return postForm(url, params, null, connTimeout, readTimeout);
}
public static String postParameters(String url, Map<String, String> params, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
SocketTimeoutException, Exception {
return postForm(url, params, null, connTimeout, readTimeout);
}
public static String get(String url) throws Exception {
return get(url, charset, null, null);
}
public static String get(String url, String charset) throws Exception {
return get(url, charset, connTimeout, readTimeout);
}
/**
* 发送一个 Post 请求, 使用指定的字符集编码.
*
* @param url
* @param body RequestBody
* @param mimeType 例如 application/xml "application/x-www-form-urlencoded" a=1&b=2&c=3
* @param charset 编码
* @param connTimeout 建立链接超时时间,毫秒.
* @param readTimeout 响应超时时间,毫秒.
* @return ResponseBody, 使用指定的字符集编码.
* @throws ConnectTimeoutException 建立链接超时异常
* @throws SocketTimeoutException 响应超时
* @throws Exception
*/
public static String post(String url, String body, String mimeType,String charset, Integer connTimeout, Integer readTimeout)
throws ConnectTimeoutException, SocketTimeoutException, Exception {
HttpClient client = null;
HttpPost post = new HttpPost(url);
String result = "";
try {
if (StringUtils.isNotBlank(body)) {
HttpEntity entity = new StringEntity(body, ContentType.create(mimeType, charset));
post.setEntity(entity);
}
// 设置参数
Builder customReqConf = RequestConfig.custom();
if (connTimeout != null) {
customReqConf.setConnectTimeout(connTimeout);
}
if (readTimeout != null) {
customReqConf.setSocketTimeout(readTimeout);
}
post.setConfig(customReqConf.build());
HttpResponse res;
if (url.startsWith("https")) {
// 执行 Https 请求.
client = createSSLInsecureClient();
res = client.execute(post);
} else {
// 执行 Http 请求.
client = HttpClientUtils.client;
res = client.execute(post);
}
result = IOUtils.toString(res.getEntity().getContent(), charset);
} finally {
post.releaseConnection();
if (url.startsWith("https") && client != null&& client instanceof CloseableHttpClient) {
((CloseableHttpClient) client).close();
}
}
return result;
}
/**
* 提交form表单
*
* @param url
* @param params
* @param connTimeout
* @param readTimeout
* @return
* @throws ConnectTimeoutException
* @throws SocketTimeoutException
* @throws Exception
*/
public static String postForm(String url, Map<String, String> params, Map<String, String> headers, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
SocketTimeoutException, Exception {
HttpClient client = null;
HttpPost post = new HttpPost(url);
try {
if (params != null && !params.isEmpty()) {
List<NameValuePair> formParams = new ArrayList<NameValuePair>();
Set<Entry<String, String>> entrySet = params.entrySet();
for (Entry<String, String> entry : entrySet) {
formParams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, Consts.UTF_8);
post.setEntity(entity);
}
if (headers != null && !headers.isEmpty()) {
for (Entry<String, String> entry : headers.entrySet()) {
post.addHeader(entry.getKey(), entry.getValue());
}
}
// 设置参数
Builder customReqConf = RequestConfig.custom();
if (connTimeout != null) {
customReqConf.setConnectTimeout(connTimeout);
}
if (readTimeout != null) {
customReqConf.setSocketTimeout(readTimeout);
}
post.setConfig(customReqConf.build());
HttpResponse res = null;
if (url.startsWith("https")) {
// 执行 Https 请求.
client = createSSLInsecureClient();
res = client.execute(post);
} else {
// 执行 Http 请求.
client = HttpClientUtils.client;
res = client.execute(post);
}
return IOUtils.toString(res.getEntity().getContent(), "UTF-8");
} finally {
post.releaseConnection();
if (url.startsWith("https") && client != null
&& client instanceof CloseableHttpClient) {
((CloseableHttpClient) client).close();
}
}
}
/**
* 发送一个 GET 请求
*/
public static String get(String url, String charset, Integer connTimeout,Integer readTimeout)
throws ConnectTimeoutException,SocketTimeoutException, Exception {
HttpClient client = null;
HttpGet get = new HttpGet(url);
String result = "";
try {
// 设置参数
Builder customReqConf = RequestConfig.custom();
if (connTimeout != null) {
customReqConf.setConnectTimeout(connTimeout);
}
if (readTimeout != null) {
customReqConf.setSocketTimeout(readTimeout);
}
get.setConfig(customReqConf.build());
HttpResponse res = null;
if (url.startsWith("https")) {
// 执行 Https 请求.
client = createSSLInsecureClient();
res = client.execute(get);
} else {
// 执行 Http 请求.
client = HttpClientUtils.client;
res = client.execute(get);
}
result = IOUtils.toString(res.getEntity().getContent(), charset);
} finally {
get.releaseConnection();
if (url.startsWith("https") && client != null && client instanceof CloseableHttpClient) {
((CloseableHttpClient) client).close();
}
}
return result;
}
/**
* 从 response 里获取 charset
*/
@SuppressWarnings("unused")
private static String getCharsetFromResponse(HttpResponse ressponse) {
// Content-Type:text/html; charset=GBK
if (ressponse.getEntity() != null && ressponse.getEntity().getContentType() != null && ressponse.getEntity().getContentType().getValue() != null) {
String contentType = ressponse.getEntity().getContentType().getValue();
if (contentType.contains("charset=")) {
return contentType.substring(contentType.indexOf("charset=") + 8);
}
}
return null;
}
/**
* 创建 SSL连接
* @return
* @throws GeneralSecurityException
*/
private static CloseableHttpClient createSSLInsecureClient() throws GeneralSecurityException {
try {
SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
public boolean isTrusted(X509Certificate[] chain,String authType) throws CertificateException {
return true;
}
}).build();
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, new X509HostnameVerifier() {
@Override
public boolean verify(String arg0, SSLSession arg1) {
return true;
}
@Override
public void verify(String host, SSLSocket ssl)
throws IOException {
}
@Override
public void verify(String host, X509Certificate cert)
throws SSLException {
}
@Override
public void verify(String host, String[] cns,
String[] subjectAlts) throws SSLException {
}
});
return HttpClients.custom().setSSLSocketFactory(sslsf).build();
} catch (GeneralSecurityException e) {
throw e;
}
}
}
参考文章：
https://www.jianshu.com/p/7342b7a35ffc
https://www.jianshu.com/p/4a3c585a99f4
使用OkHttp发送POST请求
OkHttp与HttpClient
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