Java Post 資料請求和接收
阿新 • • 發佈:2019-01-08
這兩天在做http服務端請求操作,客戶端post資料到服務端後,服務端通過request.getParameter()進行請求,無法讀取到資料,搜尋了一下發現是因為設定為text/plain模式才導致讀取不到資料
urlConn.setRequestProperty("Content-Type","text/plain; charset=utf-8");
若設定為以下方式,則通過request.getParameter()可以讀取到資料
urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
- enctype的三種編碼
form表單中enctype屬性可以用來控制對錶單資料的傳送前的如何進行編碼,即在傳送到伺服器之前,所有字元都會進行編碼(空格轉換為 "+" 加號,特殊符號轉換為 ASCII HEX 值)。預設是application/x-www-form-urlencoded。
multipart/form-data用於傳送二進位制的檔案,其他兩種型別不能用於傳送檔案
text/plain用於傳送純文字內容,不對特殊字元進行編碼,一般用於email之類的。
application/x-www-form-urlencoded 和text/plain的區別簡單講就是一個傳送html內容,一個傳送純文字內容
- application/x-www-form-urlencoded 在傳送前編碼所有字元(預設)
- multipart/form-data 不對字元編碼。在使用包含檔案上傳控制元件的表單時,必須使用該值。
- text/plain 空格轉換為 "+" 加號,但不對特殊字元編碼。
- 當定義enctype為application/x-www-form-urlencoded時,使用以下方式接收資料
request.getParameter(引數名);
- 當定義enctype為text/plain時,使用以下方式接收資料
// 接收請求資料
BufferedReader reader = request.getReader();
char[] buf = new char[512];
int len = 0;
StringBuffer contentBuffer = new StringBuffer();
while ((len = reader.read(buf)) != -1) {
contentBuffer.append(buf, 0, len);
}
String content = contentBuffer.toString();
if(content == null){
content = "";
}
- post 與get
post和get可以通過鍵值對的方式進行引數傳輸,服務端通過request.getparameter方式進行請求獲取資料。
- 客戶端post資料到服務端,服務端接收處理
public class UrlConnection {
@SuppressWarnings("finally")
public static boolean response(String url,String content) {
String line = "";
String message = "";
String returnData = "";
boolean postState = false;
BufferedReader bufferedReader = null;
try {
URL urlObject = new URL(url);
HttpURLConnection urlConn = (HttpURLConnection) urlObject.openConnection();
urlConn.setDoOutput(true);
/*設定禁用快取*/
urlConn.setRequestProperty("Pragma:", "no-cache");
urlConn.setRequestProperty("Cache-Control", "no-cache");
/*維持長連線*/
urlConn.setRequestProperty("Connection", "Keep-Alive");
/*設定字符集*/
urlConn.setRequestProperty("Charset", "UTF-8");
/*設定輸出格式為json*/
urlConn.setRequestProperty("Content-Type", "application/json;charset=utf-8");
/*設定使用POST的方式傳送*/
urlConn.setRequestMethod("POST");
/*設定不使用快取*/
urlConn.setUseCaches(false);
/*設定容許輸出*/
urlConn.setDoOutput(true);
/*設定容許輸入*/
urlConn.setDoInput(true);
urlConn.connect();
OutputStreamWriter outStreamWriter = new OutputStreamWriter(urlConn.getOutputStream(),"UTF-8");
outStreamWriter.write(content);
outStreamWriter.flush();
outStreamWriter.close();
/*若post失敗*/
if((urlConn.getResponseCode() != 200)){
returnData = "{\"jsonStrStatus\":0,\"processResults\":[]}";
message = "傳送POST失敗!"+ "code="+urlConn.getResponseCode() + "," + "失敗訊息:"+ urlConn.getResponseMessage();
// 定義BufferedReader輸入流來讀取URL的響應
InputStream errorStream = urlConn.getErrorStream();
if(errorStream != null)
{
InputStreamReader inputStreamReader = new InputStreamReader(errorStream,"utf-8");
bufferedReader = new BufferedReader(inputStreamReader);
while ((line = bufferedReader.readLine()) != null) {
message += line;
}
inputStreamReader.close();
}
errorStream.close();
System.out.println("傳送失敗!錯誤資訊為:"+message);
}else{
/*傳送成功返回傳送成功狀態*/
postState = true;
// 定義BufferedReader輸入流來讀取URL的響應
InputStream inputStream = urlConn.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream,"utf-8");
bufferedReader = new BufferedReader(inputStreamReader);
while ((line = bufferedReader.readLine()) != null) {
message += line;
}
returnData = message;
inputStream.close();
inputStreamReader.close();
System.out.println("傳送POST成功!返回內容為:" + message);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
try {
if (bufferedReader != null) {
bufferedReader.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
return postState;
}
}
/*讀取request資料*/
public static String getRequestData(HttpServletRequest request) throws IOException{
BufferedReader reader = request.getReader();
char[] buf = new char[512];
int len = 0;
StringBuffer contentBuffer = new StringBuffer();
while ((len = reader.read(buf)) != -1) {
contentBuffer.append(buf, 0, len);
}
String content = contentBuffer.toString();
if(content == null){
content = "";
}
return content;
}
}