轉-spring boot web相關配置

時間 2019-12-14

標籤 spring boot web 相關配置欄目 Spring 简体版

原文原文鏈接

spring boot web相關配置

spring boot集成了servlet容器，當咱們在pom文件中增長spring-boot-starter-web的maven依賴時，不作任何web相關的配置便能提供web服務，這還得歸於spring boot 自動配置的功能（由於加了EnableAutoConfiguration的註解），幫咱們建立了一堆默認的配置，之前在web.xml中配置，如今均可以經過spring bean的方式進行配置，由spring來進行生命週期的管理，大多數狀況下，咱們須要重載這些配置（例如修改服務的啓動端口，contextpath,filter,listener,servlet,session超時時間等）html

1. servlet配置java

當應用只有默認的servlet（即DispatcherServlet）時，映射的url爲/,存在其餘的servlet時，映射的路徑爲servlet的註冊的beanname(可經過@Component註解修改)，建立方式以下：git

[java] view plain copy

@Component("myServlet")
public class MyServlet implements Servlet{
/**
*
* @see javax.servlet.Servlet#destroy()
*/
@Override
public void destroy() {
System.out.println("destroy...");
}
/**
* @return
* @see javax.servlet.Servlet#getServletConfig()
*/
@Override
public ServletConfig getServletConfig() {
return null;
}
/**
* @return
* @see javax.servlet.Servlet#getServletInfo()
*/
@Override
public String getServletInfo() {
return null;
}
/**
* @param arg0
* @throws ServletException
* @see javax.servlet.Servlet#init(javax.servlet.ServletConfig)
*/
@Override
public void init(ServletConfig arg0) throws ServletException {
System.out.println("servlet init...");
}
/**
* @param arg0
* @param arg1
* @throws ServletException
* @throws IOException
* @see javax.servlet.Servlet#service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
*/
@Override
public void service(ServletRequest arg0, ServletResponse arg1) throws ServletException,
IOException {
System.out.println("service...");
}

2. filter配置github

filter配置的映射是/*，建立方式以下：web

[java] view plain copy

@Component("myFilter")
public class MyFilter implements Filter{
/**
*
* @see javax.servlet.Filter#destroy()
*/
@Override
public void destroy() {
System.out.println("destroy...");
}
/**
* @param arg0
* @param arg1
* @param arg2
* @throws IOException
* @throws ServletException
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException,
ServletException {
System.out.println("doFilter...");
arg2.doFilter(arg0, arg1);
}
/**
* @param arg0
* @throws ServletException
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
@Override
public void init(FilterConfig arg0) throws ServletException {
System.out.println("filter init...");
}
}<span style="font-family: Arial, Helvetica, FreeSans, sans-serif; font-size: 13.3333330154419px; line-height: 17.3333339691162px; background-color: transparent;"> </span>

3. listener配置spring

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@Component("myListener")
public class MyListener implements ServletContextListener{
/**
* @param arg0
* @see javax.servlet.ServletContextListener#contextDestroyed(javax.servlet.ServletContextEvent)
*/
@Override
public void contextDestroyed(ServletContextEvent arg0) {
System.out.println("contextDestroyed...");
}
/**
* @param arg0
* @see javax.servlet.ServletContextListener#contextInitialized(javax.servlet.ServletContextEvent)
*/
@Override
public void contextInitialized(ServletContextEvent arg0) {
System.out.println("listener contextInitialized...");
}
}

若是以爲控制力度不夠靈活（例如你想修改filter的映射），spring boot還提供了 ServletRegistrationBean，FilterRegistrationBean，ServletListenerRegistrationBean這3個東西來進行配置

修改filter的映射json

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@Configuration
public class WebConfig {
@Bean
public FilterRegistrationBean filterRegistrationBean(MyFilter myFilter){
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
filterRegistrationBean.setFilter(myFilter);
filterRegistrationBean.setEnabled(true);
filterRegistrationBean.addUrlPatterns("/bb");
return filterRegistrationBean;
}
}

4. 配置servlet 容器springboot

能夠經過兩種方式配置servlet容器，一種是經過properties文件，例如：session

[java] view plain copy

server.port=8081
server.address=127.0.0.1
server.sessionTimeout=30
server.contextPath=/springboot

完整的配置信息能夠看這 http://github.com/spring-projects/spring-boot/tree/master/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

另外一種方式是java代碼的形式：app

[java] view plain copy

@Component
public class MyCustomizationBean implements EmbeddedServletContainerCustomizer {
/**
* @param container
* @see org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizer#customize(org.springframework.boot.context.embedded.ConfigurableEmbeddedServletContainer)
*/
@Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.setContextPath("/sprintboot");
container.setPort(8081);
container.setSessionTimeout(30);
}
}

5. error 處理

spring boot 提供了/error映射來進行錯誤處理，它會返回一個json來對錯誤信息進行描述（包含了http狀態和異常信息）,例如404的錯誤

固然能夠定製錯誤頁面，經過實現ErrorController接口，並將它裝配起來便可，以下：

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@Controller
public class ErrorHandleController implements ErrorController {
/**
* @return
* @see org.springframework.boot.autoconfigure.web.ErrorController#getErrorPath()
*/
@Override
public String getErrorPath() {
return "/screen/error";
}
@RequestMapping
public String errorHandle(){
return getErrorPath();
}
}

還能夠這樣：

[java] view plain copy

@Component
private class MyCustomizer implements EmbeddedServletContainerCustomizer {
@Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.addErrorPages(new ErrorPage(HttpStatus.BAD_REQUEST, "/screen/error"));
}
}