HttpURLConnection调用rest webservice

项目之间通过url映射暴露接口，调用接口后通过json串进行数据的传递。

由于是url形式的调用，所以我们可以比较简单的应用HttpURLConnection进行数据的获取，在把获取的json语句利用jackson json或者是阿里巴巴的fastjson来进行反向对应类型的解析接口得到相应的数据。

本就简单的记录下封装HttpURLConnection获取数据的方式。

首先我们定义自己的HttpResponse类，用来获取各种web参数及数据内容

public class HttpResponse {

String urlString;

int defaultPort;

String file;

String host;

String path;

int port;

String protocol;

String query;

String ref;

String userInfo;

String contentEncoding;

String content;

String contentType;

int code;

String message;

String method;

int connectTimeout;

int readTimeout;

Vector<String> contentCollection;

public String getContent() {
return content;
}

public String getContentType() {
return contentType;
}

public int getCode() {
return code;
}

public String getMessage() {
return message;
}

public Vector<String> getContentCollection() {
return contentCollection;
}

public String getContentEncoding() {
return contentEncoding;
}

public String getMethod() {
return method;
}

public int getConnectTimeout() {
return connectTimeout;
}

public int getReadTimeout() {
return readTimeout;
}

public String getUrlString() {
return urlString;
}

public int getDefaultPort() {
return defaultPort;
}

public String getFile() {
return file;
}

public String getHost() {
return host;
}

public String getPath() {
return path;
}

public int getPort() {
return port;
}

public String getProtocol() {
return protocol;
}

public String getQuery() {
return query;
}

public String getRef() {
return ref;
}

public String getUserInfo() {
return userInfo;
}

}

接着我们就来真正的封装HttpURLConnection类来实现web数据的获取。

public class HttpRequester {
private String defaultContentEncoding;
public String getDefaultContentEncoding() {
return this.defaultContentEncoding;
}
public void setDefaultContentEncoding(String defaultContentEncoding) {
this.defaultContentEncoding = defaultContentEncoding;
}

public HttpRequester() {
this.defaultContentEncoding = Charset.defaultCharset().name();
}
//====================GET===============>=======<
public HttpResponse sendGet(String urlString) throws IOException {
return this.send(urlString, "GET", null, null);
}
public HttpResponse sendGet(String urlString, Map<String, String> params) throws IOException {
return this.send(urlString, "GET", params, null);
}
public HttpResponse sendGet(String urlString, Map<String, String> params, Map<String, String> propertys) throws IOException {
return this.send(urlString, "GET", params, propertys);
}
//====================POST===============>=======<
public HttpResponse sendPost(String urlString) throws IOException {
return this.send(urlString, "POST", null, null);
}
public HttpResponse sendPost(String urlString, Map<String, String> params) throws IOException {
return this.send(urlString, "POST", params, null);
}
public HttpResponse sendPost(String urlString, Map<String, String> params, Map<String, String> propertys) throws IOException {
return this.send(urlString, "POST", params, propertys);
}
//====================核心函数===============>=======<
private HttpResponse send(String urlString, String method, Map<String, String> parameters, Map<String, String> propertys) throws IOException {
HttpURLConnection urlConnection = null;

if (method.equalsIgnoreCase("GET") && parameters != null) {
StringBuffer param = new StringBuffer();
int i = 0;
for (String key : parameters.keySet()) {
if (i == 0)
param.append("?");
else
param.append("&");
param.append(key).append("=").append(parameters.get(key));
i++;
}
urlString += param;
}
URL url = new URL(urlString);
urlConnection = (HttpURLConnection) url.openConnection();

urlConnection.setRequestMethod(method);
urlConnection.setDoOutput(true);
urlConnection.setDoInput(true);
urlConnection.setUseCaches(false);

if (propertys != null)
for (String key : propertys.keySet()) {
urlConnection.addRequestProperty(key, propertys.get(key));
}

if (method.equalsIgnoreCase("POST") && parameters != null) {
StringBuffer param = new StringBuffer();
for (String key : parameters.keySet()) {
param.append("&");
param.append(key).append("=").append(parameters.get(key));
}
urlConnection.getOutputStream().write(param.toString().getBytes());
urlConnection.getOutputStream().flush();
urlConnection.getOutputStream().close();
}

return this.makeContent(urlString, urlConnection);
}

private HttpResponse makeContent(String urlString, HttpURLConnection urlConnection) throws IOException {
HttpResponse httpResponser = new HttpResponse();
try {
InputStream in = urlConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(in));
httpResponser.contentCollection = new Vector<String>();
StringBuffer temp = new StringBuffer();
String line = bufferedReader.readLine();
while (line != null) {
httpResponser.contentCollection.add(line);
temp.append(line).append("\r\n");
line = bufferedReader.readLine();
}
bufferedReader.close();

String ecod = urlConnection.getContentEncoding();
if (ecod == null)
ecod = this.defaultContentEncoding;

httpResponser.urlString = urlString;

httpResponser.defaultPort = urlConnection.getURL().getDefaultPort();
httpResponser.file = urlConnection.getURL().getFile();
httpResponser.host = urlConnection.getURL().getHost();
httpResponser.path = urlConnection.getURL().getPath();
httpResponser.port = urlConnection.getURL().getPort();
httpResponser.protocol = urlConnection.getURL().getProtocol();
httpResponser.query = urlConnection.getURL().getQuery();
httpResponser.ref = urlConnection.getURL().getRef();
httpResponser.userInfo = urlConnection.getURL().getUserInfo();

httpResponser.content = new String(temp.toString().getBytes(), ecod);
httpResponser.contentEncoding = ecod;
httpResponser.code = urlConnection.getResponseCode();
httpResponser.message = urlConnection.getResponseMessage();
httpResponser.contentType = urlConnection.getContentType();
httpResponser.method = urlConnection.getRequestMethod();
httpResponser.connectTimeout = urlConnection.getConnectTimeout();
httpResponser.readTimeout = urlConnection.getReadTimeout();

return httpResponser;
} catch (IOException e) {
throw e;
} finally {
if (urlConnection != null)
urlConnection.disconnect();
}
}
}

获取json格式的web数据后，我们逆解析得到封装相应数据的类。

String json = null;

HttpRequester request = new HttpRequester();

try {

HttpResponse hr = request.sendGet(pathStr);

json = hr.content;

//要找到json串的第一个“{”和最后一个“}”，不然会报错。

json=json.substring(json.indexOf("[")+1, json.indexOf("]"));

//alibaba的fastjson解析

XxxClass pro = JSON.parseObject(json, XxxClass.class);

} catch (IOException e) {

e.printStackTrace();

}