一般elasticsearch是没有设置用户名、密码的，数据有安全性问题。需要给elasticsearch访问的时候设置用户名、密码。当用kibana访问时需要输入用户名、密码后才能登录。
1、修改elasticsearch.yml(报无效认证)，重启elasticsearch
http.cors.enabled: true
http.cors.allow-origin: "*"
http.cors.allow-headers: Authorization
xpack.security.enabled: true
xpack.security.transport.ssl.enabled: true如上修改后，双击启动elasticsearch.bat文件报如下错：
elasitcsearch 开启认证后，报DecoderException: javax.net.ssl.SSLHandshakeException: No available authentic异常
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解决办法参考：elasitcsearch 开启认证后，报DecoderException: javax.net.ssl.SSLHandshakeException: No available authentic异常_猿界汪汪队的博客
第一步：在ES的根目录生成CA证书
elasticsearch-7.4.2\bin>elasticsearch-certutil ca
中间需要设置密码，直接回车可以不设置（慎重考虑）。
第二步：使用第一步生成的证书，产生p12密钥
elasticsearch-7.4.2\bin>elasticsearch-certutil cert --ca elastic-stack-ca.p12
此时文件大概如下：
第三步：在config目录下创建certs目录
第四步：拷贝两个p12文件至certs目录
第五步：修改设置
修改elasticsearch.yml配置如下(http开头的不改，替换xpack开头的就行)：
xpack.security.enabled: true
xpack.license.self_generated.type: basic
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.keystore.path: certs/elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: certs/elastic-certificates.p12第六步：重启ES,错误消失
2、修改elasticsearch密码(要java11问题解决),重启elasticsearch
elasticsearch-7.4.2\bin>elasticsearch-setup-passwords interactive
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解决方法参考：
ElasticSearch 提示 future versions of Elasticsearch will require Java 11解决方法_AB教程网 如果是window系统，打开elasticsearch-env.bat
找到42行，注释掉默认使用系统的jdk的设置，增加使用es里自带的jdk11
我的修改如下：
if defined JAVA_HOME (
rem set JAVA="%JAVA_HOME%\bin\java.exe"
set JAVA="C:\Users\lenovo\Desktop\QWJS\Archive\elasticsearch-7.5.1\jdk\bin\java.exe"
set JAVA_TYPE=JAVA_HOME
) else (
rem set JAVA="%ES_HOME%\jdk\bin\java.exe"
set JAVA="C:\Users\lenovo\Desktop\QWJS\Archive\elasticsearch-7.5.1\jdk\bin\java.exe"
rem set JAVA_HOME="%ES_HOME%\jdk"
set JAVA_HOME="C:\Users\lenovo\Desktop\QWJS\Archive\elasticsearch-7.5.1\jdk"
set JAVA_TYPE=bundled jdk
)3、给elasticsearch设置密码(前提执行了前面1、2、然后启动elasticsearch成功的状态下)
参考网址：
设置elasticsearch 7.x用户名和密码_程裕强的博客_elasticsearch密码设置
elasticsearch-7.4.2\bin>elasticsearch-setup-passwords interactive
D:\app\elasticsearch-7.4.2\bin>elasticsearch-setup-passwords interactive
Initiating the setup of passwords for reserved users elastic,apm_system,kibana,logstash_system,beats_system,remote_monitoring_user.
You will be prompted to enter passwords as the process progresses.
Please confirm that you would like to continue [y/N]y
Enter password for [elastic]:
Reenter password for [elastic]:
Enter password for [apm_system]:
Reenter password for [apm_system]:
Enter password for [kibana]:
Reenter password for [kibana]:
Enter password for [logstash_system]:
Reenter password for [logstash_system]:
Enter password for [beats_system]:
Reenter password for [beats_system]:
Enter password for [remote_monitoring_user]:
Reenter password for [remote_monitoring_user]:
Changed password for user [apm_system]
Changed password for user [kibana]
Changed password for user [logstash_system]
Changed password for user [beats_system]
Changed password for user [remote_monitoring_user]
Changed password for user [elastic]
D:\app\elasticsearch-7.4.2\bin>密码修改完成后、访问elasticsearch。
浏览器输入http://localhost:9200需要输入用户名：elastic 密码：自己设置的密码
4、连接elasticsearch的插件Kibana设置链接的地址跟连接用户名，启动后访问全文检索数据
修改kibana组件config文件夹下kibana.yml
修改完成保存后，点击kibana-7.5.1-windows-x86_64\bin下面的kibana.bat启动
浏览器访问http://localhost:8088/，输入登陆用户名：elastic 密码：前面elasticsearch设置的密码
登陆后查看索引库信息：
5、由于elasticsearch设置了用户名、密码，所以在全文检索的代码也要做修改把用户名、密码带进去连接全文检索
