[Java] - Google API调用

由于Google已经完成被墙，要上Google必需使用代理或VPN。

这里使用的是Google的GoAgent代理做开发。（如何使用GoAgent，这里不写了，忽略500字。。。。。）

本地测试的GoAgent地址为：127.0.0.1:8087

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一、Google的API设置

1、首先需要在Google的控制台中设置新增好Project，设置地址：

https://console.developers.google.com

2、在Permissions中设置好Service Account:

3、在APIs & Auth -> APIs中，加入所需要开放的API，如本例中使用的是ShoppingContent：

4、在APIs & Auth -> credential中生成或新增对应的键值或证书：

我这里使用的是证书形式的调用，证书的生成在Public API access当中。点生成证书key后，会导出一个p12证书。保存好这个证书到项目当中。

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二、获取Google HTTPS证书，并导入到Java JRE里头信认此证书

因为使用java访问google API是以https形式访问的，默认情况下，google的证书是不被信认的。所以需要先把google https的证书添加到java信认证书当中。

1、首先使用chrome打开这个地址：https://accounts.google.com

2、点击地址栏上的绿色锁：

3、导出https证书保存成文件：

比如说我这里保存的文件是：google.cer

4、eclipse安装插件：net.sourceforge.keytool.plugin_1.4.2.jar

插件哪里下载，自行搜索。在http://sourceforge.net/中可以下到。

如何安装eclipse插件这里忽略。

安装完后，可以在eclipse中看到：

工具栏：

下面窗口：

5、打开java的jdk证书文件，在eclipse中：

弹出窗口：

例如我本机的FileName中的位置是：C:\Program Files\Java\jdk1.7.0_51\jre\lib\security\cacerts

这里不要选错了，是JDK下的JRE下的lib，不要直接选到JRE下的lib。

默认密码为：changeit

打开后，将看到如下内容：

6、导入证书。右键->Import certificate

成功导入后将看到：

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三、编码

1、eclipse新建一个maven项目。（如何在eclipse新建maven项目这里忽略，使用maven是方便下载jar包，也可以自行上网搜索下载比较烦锁）

这里使用的是Google API的ShoppingContent做例子，所以下的Jar包为ShoppingContent，使用别的API，需要自行修改

pom.xml内容为：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.my.maven.googleapi</groupId>
  <artifactId>testapi</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>testapi</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.google.api-client</groupId>
      <artifactId>google-api-client</artifactId>
      <version>1.19.0</version>
    </dependency>
    <dependency>
        <groupId>com.google.http-client</groupId>
        <artifactId>google-http-client-jackson2</artifactId>
        <version>1.19.0</version>
    </dependency>
    <dependency>
      <groupId>com.google.apis</groupId>
      <artifactId>google-api-services-content</artifactId>
      <version>v2-rev33-1.19.1</version>
    </dependency>
  </dependencies>
</project>

下载完后的jar包大致会有这些：

2、把p12证书文件也放到项目当中：

3、Java测试类：

package com.my.maven.googleapi.testapi;

import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.math.BigInteger;
import java.net.URL;
import java.net.URLConnection;
import java.security.cert.X509Certificate;
import java.util.Collections;
import java.util.Properties;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.content.ShoppingContent;
import com.google.api.services.content.ShoppingContentScopes;
import com.google.api.services.content.model.Product;

/**
 * Hello world!
 *
 */
public class App {

    public static void main(String[] args) throws Exception {

        String strJavaHome = System.getProperty("java.home");

        Properties systemProperties = System.getProperties();
        systemProperties.setProperty("http.proxyHost", "127.0.0.1");
        systemProperties.setProperty("http.proxyPort", "8087");
        systemProperties.setProperty("https.proxyHost", "127.0.0.1");
        systemProperties.setProperty("https.proxyPort", "8087");
        systemProperties.setProperty("socksProxyHost", "127.0.0.1");
        systemProperties.setProperty("socksProxyPort", "8087");
        System.setProperty("sun.net.client.defaultConnectTimeout", String.valueOf(900000));// （单位：毫秒）

        final Credential credential = authorize();
        ShoppingContent service = new ShoppingContent.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
                .setApplicationName(APPLICATION_NAME)
//                .setHttpRequestInitializer(new HttpRequestInitializer() {
//                    public void initialize(HttpRequest httpRequest) throws IOException {
//                        httpRequest.setReadTimeout(90000000);
//                        credential.initialize(httpRequest);
//                    }
//                })
                .build();
        Product product = service.products()
                .get(merchantId, "online:en:JP:123456789").execute();
        System.out.printf("%s %s\n", product.getId(), product.getTitle());
    }

    /**
     * Be sure to specify the name of your application. If the application name
     * is {@code null} or blank, the application will log a warning. Suggested
     * format is "MyCompany-ProductName/1.0".
     */
    private static final String APPLICATION_NAME = "AdWords.MerchantCenterProxy";

    /** Global instance of the HTTP transport. */
    private static final HttpTransport HTTP_TRANSPORT = new NetHttpTransport();

    /** Global instance of the JSON factory. */
    private static final JsonFactory JSON_FACTORY = new JacksonFactory();

    private static final String SERVICE_ACCOUNT_EMAIL = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX@developer.gserviceaccount.com";

    private static final String SERVICE_ACCOUNT_USER = "XXXXXXXXXXXXXXXXXXXX@gmail.com";

    private static final BigInteger merchantId = new BigInteger("123456789");

    /** Authorizes the installed application to access user's protected data. */
    private static Credential authorize() throws Exception {
        String p12FilePath = System.getProperty("user.dir") + "\\XXXXXXXXXX.p12";
        GoogleCredential credential = new GoogleCredential.Builder()
                .setTransport(HTTP_TRANSPORT)
                .setServiceAccountPrivateKeyFromP12File(new File(p12FilePath))
                .setJsonFactory(JSON_FACTORY)
                .setServiceAccountId(SERVICE_ACCOUNT_EMAIL)
                .setServiceAccountScopes(Collections.singleton(ShoppingContentScopes.CONTENT))
                .setServiceAccountUser(SERVICE_ACCOUNT_USER)
                .build();
        credential.refreshToken();
        return credential;
    }
}

代码说明：

注意到这一段：

        Properties systemProperties = System.getProperties();
        systemProperties.setProperty("http.proxyHost", "127.0.0.1");
        systemProperties.setProperty("http.proxyPort", "8087");
        systemProperties.setProperty("https.proxyHost", "127.0.0.1");
        systemProperties.setProperty("https.proxyPort", "8087");
        systemProperties.setProperty("socksProxyHost", "127.0.0.1");
        systemProperties.setProperty("socksProxyPort", "8087");

这是设置使用代理方式连接访问google。

这句：

        System.setProperty("sun.net.client.defaultConnectTimeout", String.valueOf(900000));// （单位：毫秒）

是指连接超时设置，当然了，也可以单独使用我已经注释的这段来做单个httprequest connection readtimeout设置：

//                .setHttpRequestInitializer(new HttpRequestInitializer() {
//                    public void initialize(HttpRequest httpRequest) throws IOException {
//                        httpRequest.setReadTimeout(90000000);
//                        credential.initialize(httpRequest);
//                    }
//                })

运行输出结果：

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最后附上.net的调用方法：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Google.GData.ContentForShopping;
using Google.GData.ContentForShopping.Elements;
using Google.GData.Client;
using Google.GData.Extensions;
using AdWords.Model;
using AdWords.Config;
using System.Xml;
using Google.Apis.Auth.OAuth2;
using Google.Apis.ShoppingContent.v2;
using System.Security.Cryptography.X509Certificates;
using Google.Apis.Services;

namespace AdWords.MerchantCenterProxy
{
    public class MerchantHelper
    {
        /// <summary>
        /// Merchant Account ID
        /// </summary>
        public static ulong MerchantCenterAccountId { get { return ulong.Parse(System.Configuration.ConfigurationManager.AppSettings["MerchantCenterAccountId"]); } }

        /// <summary>
        /// 登陆状态
        /// </summary>
        private static ServiceAccountCredential credential;

        /// <summary>
        /// 取得Google API OAuth2登陆状态
        /// </summary>
        /// <returns></returns>
        public static ServiceAccountCredential GetCredential()
        {
            if (credential == null)
            {
                String serviceAccountEmail = System.Configuration.ConfigurationManager.AppSettings["GoogleApiAccountEmail"];
                String certificateFilePath = System.Configuration.ConfigurationManager.AppSettings["GoogleApiCertificateFilePath"];
                String MerchantCenteruUser = System.Configuration.ConfigurationManager.AppSettings["MerchantCenterUserName"];

                var certificate = new X509Certificate2(certificateFilePath, "notasecret", X509KeyStorageFlags.Exportable);
                credential = new ServiceAccountCredential(
                   new ServiceAccountCredential.Initializer(serviceAccountEmail)
                   {
                       User = MerchantCenteruUser,
                       Scopes = new[] { ShoppingContentService.Scope.Content }
                   }.FromCertificate(certificate));
            }

            return credential;
        }

        /// <summary>
        /// 取得ShoppingContent Service
        /// </summary>
        /// <returns></returns>
        public static ShoppingContentService GenerateShoppingContentService()
        {
            var service = new ShoppingContentService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = GetCredential(),
                ApplicationName = "AdWords.MerchantCenterProxy",
            });
            return service;
        }
    }
}

.net的Google API的dll下载，可以使用Package Manager Console中使用install命令下载得到。具体上网搜索一下即可。