HTTP Status 400 – Bad Request

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Type Status Report

Description The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).

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Apache Tomcat/8.5.12

解决：restful的增删对应的http方法分别为put及delete（边跑步边想到的。。。）

调用put方法步骤

1.修改tomcat下conf/web.xml

<servlet>

<servlet-name>default</servlet-name>

<servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>

<init-param>

<param-name>debug</param-name>

<param-value>0</param-value>

</init-param>

<init-param>

<param-name>listings</param-name>

<param-value>false</param-value>

</init-param>

<init-param>//主要是这里，默认的readonly属性是true，即不支持put方法，改为false

<param-name>readonly</param-name>

<param-value>false</param-value>

</init-param>

<load-on-startup>1</load-on-startup>

</servlet>这段代码若web.xml中已经存在就修改上面readonly节点属性即可，若没有就新加。2.修改tomcat目录下conf/tomcat-users.xml，添加用户权限，同时调用接口时也需要加上同下的权限。

<?xml version='1.0' encoding='cp1252'?>

<tomcat-users>

<user name="admin" password="admin" roles="admin" />

</tomcat-users>3.修改工程项目下的web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

version="2.5">

<security-constraint>

<web-resource-collection>

<web-resource-name>Demo App</web-resource-name>

<url-pattern>/*</url-pattern>

<http-method>PUT</http-method>

</web-resource-collection>

<auth-constraint>

<role-name>admin</role-name>

</auth-constraint>

</security-constraint>

<login-config>

<auth-method>BASIC</auth-method>

<realm-name>Demo App</realm-name>

</login-config>

<security-role>

<description>Role for restricted resources</description>

<role-name>admin</role-name>

</security-role>

</web-app>新加以上代码。至此即可调用put方法。