1配置Java环境
将你电脑的Java环境变量配置成AndroidStudio的所使用的Java环境，为什么要配置？这方便等会添加证书的时候是针对AndroidStudio所使用的Java环境（注意：如果你电脑已经配置好了JAVA_HOME，我仍然建议你暂时先配置成AndroidStudio的Java环境，因为不同的Java版本证书可能是不一致的，截止发教程前最新的AndroidStudio3.5.5版本，使用的仍是Java8，但我看到有些人的电脑已经配置到Java11了，如果你已经配置了，请暂时先记录下，然后删除，等你修复好AndroidStudio之后，再配置回来）
（1）将AndroidStudio里的jre配置成JAVA_HOME变量
打开环境变量：此电脑->属性->高级系统设置->高级->环境变量
配置环境变量：系统变量新建JAVA_HOME，输入AndroidStudio目录下Java的环境变量，然后确定保存（如图所示）
image
然后编辑一下Path环境变量，在Path环境变量分别加入%JAVA_HOME%\bin和%JAVA_HOME%\lib（如图所示）
image
（2）使用cmd检查当前的java环境，输入where java可查到java.exe所在位置
C:\Users\Administrator>where java
D:\AndroidStudio\jre\bin\java.exe
C:\Users\Administrator>
2.安装证书
2.1桌面新建一个文件夹cert，在里面新建一个文件InstallCert.java代码如下
/*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.*;
import java.security.*;
import java.security.cert.*;
import javax.net.ssl.*;
public class InstallCert {
public static void main(String[] args) throws Exception {
String host = "10.0.31.32"; //输入服务端地址
int port = 443; //输入服务端端口 一般默认443
String p = "changeit"; //一般默认changeit
char[] passphrase = p.toCharArray();
File file = new File("jssecacerts");
if (file.isFile() == false) {
char SEP = File.separatorChar;
File dir = new File(System.getProperty("java.home") + SEP
+ "lib" + SEP + "security");
file = new File(dir, "jssecacerts");
if (file.isFile() == false) {
file = new File(dir, "cacerts");
}
}
System.out.println("Loading KeyStore " + file + "...");
InputStream in = new FileInputStream(file);
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(in, passphrase);
in.close();
SSLContext context = SSLContext.getInstance("TLS");
TrustManagerFactory tmf =
TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(ks);
X509TrustManager defaultTrustManager = (X509TrustManager)tmf.getTrustManagers()[0];
SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);
context.init(null, new TrustManager[] {tm}, null);
SSLSocketFactory factory = context.getSocketFactory();
System.out.println("Opening connection to " + host + ":" + port + "...");
SSLSocket socket = (SSLSocket)factory.createSocket(host, port);
socket.setSoTimeout(10000);
try {
System.out.println("Starting SSL handshake...");
socket.startHandshake();
socket.close();
System.out.println();
System.out.println("No errors, certificate is already trusted");
} catch (SSLException e) {
System.out.println();
e.printStackTrace(System.out);
}
X509Certificate[] chain = tm.chain;
if (chain == null) {
System.out.println("Could not obtain server certificate chain");
return;
}
BufferedReader reader =
new BufferedReader(new InputStreamReader(System.in));
System.out.println();
System.out.println("Server sent " + chain.length + " certificate(s):");
System.out.println();
MessageDigest sha1 = MessageDigest.getInstance("SHA1");
MessageDigest md5 = MessageDigest.getInstance("MD5");
for (int i = 0; i < chain.length; i++) {
X509Certificate cert = chain[i];
System.out.println
(" " + (i + 1) + " Subject " + cert.getSubjectDN());
System.out.println(" Issuer " + cert.getIssuerDN());
sha1.update(cert.getEncoded());
System.out.println(" sha1 " + toHexString(sha1.digest()));
md5.update(cert.getEncoded());
System.out.println(" md5 " + toHexString(md5.digest()));
System.out.println();
}
System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");
String line = reader.readLine().trim();
int k;
try {
k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;
} catch (NumberFormatException e) {
System.out.println("KeyStore not changed");
return;
}
X509Certificate cert = chain[k];
String alias = host + "-" + (k + 1);
ks.setCertificateEntry(alias, cert);
OutputStream out = new FileOutputStream("jssecacerts");
ks.store(out, passphrase);
out.close();
System.out.println();
System.out.println(cert);
System.out.println();
System.out.println
("Added certificate to keystore 'jssecacerts' using alias '"
+ alias + "'");
}
private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();
private static String toHexString(byte[] bytes) {
StringBuilder sb = new StringBuilder(bytes.length * 3);
for (int b : bytes) {
b &= 0xff;
sb.append(HEXDIGITS[b >> 4]);
sb.append(HEXDIGITS[b & 15]);
sb.append(' ');
}
return sb.toString();
}
private static class SavingTrustManager implements X509TrustManager {
private final X509TrustManager tm;
private X509Certificate[] chain;
SavingTrustManager(X509TrustManager tm) {
this.tm = tm;
}
public X509Certificate[] getAcceptedIssuers() {
throw new UnsupportedOperationException();
}
public void checkClientTrusted(X509Certificate[] chain, String authType)
throws CertificateException {
throw new UnsupportedOperationException();
}
public void checkServerTrusted(X509Certificate[] chain, String authType)
throws CertificateException {
this.chain = chain;
tm.checkServerTrusted(chain, authType);
}
}
}
2.2修改代码
- 在本例中，我在桌面新建了一个Cert文件夹，我把InstallCert.java放到了Cert文件夹中，便于修改和管理
- 修改InstallCert.java代码中"10.0.31.32"为你在AndroidStudio中无法验证证书的域名，改完后应该是下面这样的
String host = "jcenter.bintray.com"; //输入服务端地址
int port = 443; //输入服务端端口 一般默认443
（注意，你的可能是"dl.google.com"或者是"d29vzk4ow07wi7.cloudfront.net"，具体的需要看它报错的域名，如果你是第一次安装，请一次性加完三个域名再进行后面的操作，也就是你需要进行三次javac和三次java命令，这样出错的概率会非常低）
image
2.3获取证书
-
当你修改好并保存文件之后，使用cmd进入到桌面的Cert目录，输入命令javac InstallCert.java，然后按回车来编译它
2.4替换证书文件
<meta charset="utf-8">
打开AndroidStudio的安装目录，进入到jre->jre->lib->security里，将cacerts重命名成cacerts1，然后把jssecacerts拷贝到当前目录，并命名成cacerts
image
3.刷新AndroidStudio缓存，使配置生效
回到AndroidStudio，选择“File -> Invalidate Caches / Restart”，这个时候，AndroidStudio会自动重启，如果你的Gradle进程没有再运行，并且运行按钮是灰色的，请点击“File -> Sync Project with Gradle Files”
image
到这一步，问题基本已经解决【请注意，如果你Invalidate Caches / Restart之后，还遇到这个问题，你应该查看错误的域名是不是变了，一般是变成你没添加过的域名，例如：你添加了jcenter.bintrary.com，但你做完以上操作之后，错误的域名变成dl.google.com或者d29vzk4ow07wi7.cloudfront.net，那么你需要再次添加其它域名的证书，一般出现这个错误，那么你通常是要进行三次添加证书操作，然后三次Invalidate Caches / Restart才能解决，如果依旧错误，可能是操作有误，可以加我Q群问问哈，例如有多个java环境，可能会导致你卡在无法使用java InstallCert命令】（完）
作者：Analyas
链接：https://www.jianshu.com/p/89ca5b635d3f
来源：简书
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