导语：上一章节我们了解了怎么手动拼接请求URL和用API2.0签名自动生成请求URL，来调用CKafka的接口，这一章将进入开发阶段，用java实现拼接请求URL，进行API调用。
一、申请安全凭证
在第一次使用腾讯云 API 之前，用户需要在【腾讯云控制台】> 【API 密钥管理 】上申请安全凭证。安全凭证包括 SecretId 和 SecretKey，其中：
- SecretId：用于标识 API 调用者身份。
- SecretKey：用于加密签名字符串和服务器端验证签名字符串的密钥。
注意： API 密钥是构建腾讯云 API 请求的重要凭证，使用腾讯云 API 可以操作您名下的所有腾讯云资源，为了您的财产和服务安全，请妥善保存并定期更换密钥，当您更换密钥后，请及时删除旧密钥。
二、生成签名串请求参数 (Signature)
1. 对参数排序
代码语言：javascript复制 /* 对参数排序 方法一*/
public static String mapSortedByKey(Map<String, String> param) {
StringBuilder stringBuilder = new StringBuilder();
ArrayList<String> keyList = new ArrayList<>(param.keySet());
Collections.sort(keyList);
for (int i = 0; i < keyList.size(); i ) {
String key = keyList.get(i);
if (i == keyList.size() - 1) {
stringBuilder.append(key).append("=").append(param.getOrDefault(key, ""));
} else {
stringBuilder.append(key).append("=").append(param.getOrDefault(key, "")).append("&");
}
}
return stringBuilder.toString();
}
/* 对参数排序 方法二*/
public static void sortMap(Map<String, String> param) {
TreeMap<String, String> paramTreeMap = new TreeMap<>(param);
System.out.println(paramTreeMap);
}2. 拼接签名原文字符串
代码语言：javascript复制 /* 拼接请求URL */
public static String getRqstUrl(String method, List list) {
StringBuilder builder = new StringBuilder();
boolean isFirst = true;
builder.append(method);
for (int i=0;i<list.size();i ) {
if(i==0) {
builder.append(list.get(i));
}else if (i==1) {
builder.append("?");
builder.append(list.get(i));
}else {
builder.append("&");
builder.append(list.get(i));
}
}
return builder.toString();
}
3. 生成签名串
代码语言：javascript复制 /* 生成签名串 */
public static String sha256_HMAC(String message, String secret) {
String hash="";
try {
Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
SecretKeySpec secret_key = new SecretKeySpec(secret.getBytes(), "HmacSHA256");
sha256_HMAC.init(secret_key);
hash = Base64.encodeBase64String(sha256_HMAC.doFinal(message.getBytes()));
System.out.println(hash);
}
catch (Exception e){
System.out.println("Error");
}
return hash;
}
三、签名串URL编码
代码语言：javascript复制/* URL 编码: */
public static String getURLEncoderString(String str) {
String result = "";
if (null == str) {
return "";
}
try {
result = java.net.URLEncoder.encode(str, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}
/* URL 解码: */
public static String URLDecoderString(String str) {
String result = "";
if (null == str) {
return "";
}
try {
result = java.net.URLDecoder.decode(str, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}
四、调用GET方式请求URL
代码语言：javascript复制/* 执行URL请求 */
public static String sendGet(String url) {
String result = "";
BufferedReader in = null;
try {
String urlNameString = url;
URL realUrl = new URL(urlNameString);
URLConnection connection = realUrl.openConnection();
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
connection.connect();
Map<String, List<String>> map = connection.getHeaderFields();
for (String key : map.keySet()) {
System.out.println(key "--->" map.get(key));
}
in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result = line;
}
} catch (Exception e) {
e.printStackTrace();
}
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return result;
}五、调用获取主题列表接口
代码语言：javascript复制import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
public class ToInterface {
private final static String secretId="AKIDKTM0OYJ6SaaKnyxxxxxxxxxxxxxxxxx";
private final static String secretKey="WmmW0wd4E8nCKEPxxxxxxxxxxxxxxx";
/* main方法 */
public static void main(String[] args) {
int times=(int) (System.currentTimeMillis()/1000);
String timestamp=String.valueOf(times);
String nonce=timestamp;
//获取消费分组 offset接口
//String str3=GetGroupOffsets(nonce,timestamp);
//调用获取主题列表接口
String str3=GetListTopic(nonce,timestamp);
System.out.println(str3);
}
//获取主题列表接口
public static String GetListTopic(String nonce,String timestamp) {
String url="ckafka.api.zijiebao.com/v2/index.php";
String signatureMethod="HmacSHA256";
String instanceId="ckafka-3vekxxxx";
Map<String, String> param = new HashMap<>();
param.put("Action", "ListTopic");
param.put("Nonce", nonce);
param.put("instanceId",instanceId);
param.put("Timestamp",timestamp);
param.put("SignatureMethod", signatureMethod);
param.put("Region", "ap-guangzhou");
param.put("SecretId", secretId);
return getResult(param,url);
}
/* 获取消费分组 offset接口 */
public static String GetGroupOffsets(String nonce,String timestamp) {
String url="ckafka.api.zijiebao.com/v2/index.php";
String signatureMethod="HmacSHA256";
String instanceId="ckafka-3vekxxxx";
Map<String, String> param = new HashMap<>();
param.put("Action", "GetGroupOffsets");
param.put("Nonce", nonce);
param.put("instanceId",instanceId);
param.put("Timestamp",timestamp);
param.put("SignatureMethod", signatureMethod);
param.put("Region", "ap-guangzhou");
param.put("SecretId", secretId);
param.put("group", "console-consumer-2529");
return getResult(param,url);
}
/* 执行调用 */
public static String getResult(Map<String, String> param,String url) {
String strparam=mapSortedByKey(param);
List list=new ArrayList();
list.add(url);
list.add(strparam);
//System.out.println(list.get(0));
String str=getRqstUrl("GET",list);
System.out.println(str);
String signature1= getURLEncoderString(sha256_HMAC(str,secretKey));
list.add("Signature=" signature1);
String str2=getRqstUrl("https://",list);
String str3 =sendGet(str2);
return str3;
}
}执行结果：有3个topic，显示有topicId和topicName、note
代码语言：javascript复制{"code":0,"message":"","codeDesc":"Success",
"data":{"totalCount":3,"topicList":[
{"topicId":"topic-7p2pzlo4","topicName":"topic_test1","note":""},
{"topicId":"inter-topic-kfjiqvgo","topicName":"bowenqiu_test1","note":""},
{"topicId":"topic-3yueh1ge","topicName":"bowenqiu_topic1","note":"bowenqiu_topic1"}]}}
