在实际的web应用程序中，经常需要在请求（request）外面增加包装用于：记录调用日志、排除有XSS威胁的字符、执行权限验证等等。除了上述提到的之外，Spring Boot自动添加了OrderedCharacterEncodingFilter和HiddenHttpMethodFilter，并且我们在自己的项目中还可以增加别的过滤器。
Servlet注册
使用Spring Boot中自带的Servlet注册Bean进行Servlet注册
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
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package org.springframework.boot.web.servlet;
import java.util.Arrays;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;
import javax.servlet.MultipartConfigElement;
import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration.Dynamic;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.boot.web.servlet.RegistrationBean;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
public class ServletRegistrationBean extends RegistrationBean {
private static final Log logger = LogFactory.getLog(ServletRegistrationBean.class);
private static final String[] DEFAULT_MAPPINGS = new String[]{"/*"};
private Servlet servlet;
private Set<String> urlMappings;
private boolean alwaysMapUrl;
private int loadOnStartup;
private MultipartConfigElement multipartConfig;
public ServletRegistrationBean() {
this.urlMappings = new LinkedHashSet();
this.alwaysMapUrl = true;
this.loadOnStartup = -1;
}
public ServletRegistrationBean(Servlet servlet, String... urlMappings) {
this(servlet, true, urlMappings);
}
public ServletRegistrationBean(Servlet servlet, boolean alwaysMapUrl, String... urlMappings) {
this.urlMappings = new LinkedHashSet();
this.alwaysMapUrl = true;
this.loadOnStartup = -1;
Assert.notNull(servlet, "Servlet must not be null");
Assert.notNull(urlMappings, "UrlMappings must not be null");
this.servlet = servlet;
this.alwaysMapUrl = alwaysMapUrl;
this.urlMappings.addAll(Arrays.asList(urlMappings));
}
protected Servlet getServlet() {
return this.servlet;
}
public void setServlet(Servlet servlet) {
Assert.notNull(servlet, "Servlet must not be null");
this.servlet = servlet;
}
public void setUrlMappings(Collection<String> urlMappings) {
Assert.notNull(urlMappings, "UrlMappings must not be null");
this.urlMappings = new LinkedHashSet(urlMappings);
}
public Collection<String> getUrlMappings() {
return this.urlMappings;
}
public void addUrlMappings(String... urlMappings) {
Assert.notNull(urlMappings, "UrlMappings must not be null");
this.urlMappings.addAll(Arrays.asList(urlMappings));
}
public void setLoadOnStartup(int loadOnStartup) {
this.loadOnStartup = loadOnStartup;
}
public void setMultipartConfig(MultipartConfigElement multipartConfig) {
this.multipartConfig = multipartConfig;
}
public MultipartConfigElement getMultipartConfig() {
return this.multipartConfig;
}
public String getServletName() {
return this.getOrDeduceName(this.servlet);
}
public void onStartup(ServletContext servletContext) throws ServletException {
Assert.notNull(this.servlet, "Servlet must not be null");
String name = this.getServletName();
if(!this.isEnabled()) {
logger.info("Servlet " + name + " was not registered (disabled)");
} else {
logger.info("Mapping servlet: \'" + name + "\' to " + this.urlMappings);
Dynamic added = servletContext.addServlet(name, this.servlet);
if(added == null) {
logger.info("Servlet " + name + " was not registered (possibly already registered?)");
} else {
this.configure(added);
}
}
}
protected void configure(Dynamic registration) {
super.configure(registration);
String[] urlMapping = (String[])this.urlMappings.toArray(new String[this.urlMappings.size()]);
if(urlMapping.length == 0 && this.alwaysMapUrl) {
urlMapping = DEFAULT_MAPPINGS;
}
if(!ObjectUtils.isEmpty(urlMapping)) {
registration.addMapping(urlMapping);
}
registration.setLoadOnStartup(this.loadOnStartup);
if(this.multipartConfig != null) {
registration.setMultipartConfig(this.multipartConfig);
}
}
}注册Servlet
@Bean
public ServletRegistrationBean druidStatViewServlet(DruidDataSourceProperties druidDataSourceProperties) {
if (StringUtils.isEmpty(druidDataSourceProperties.getServletPath())) {
druidDataSourceProperties.setServletPath("/druid/*");
}
return new ServletRegistrationBean(new StatViewServlet(), druidDataSourceProperties.getServletPath());
}其中StatViewServlet就是我们需要注册的Servlet，DruidDataSourceProperties.getServletPath()设置对应访问该Servlet的Url
Filter注册
1、直接将实现javax.servlet.Filter注册为Spring Bean
@Bean
public FilterRegistrationBean druidWebStatFilter() {
return new WebStatFilter();
}但是这样过滤器过来的Url为/**。如果我不想过滤所有的连接，请看第二种方式.
2、使用Spring Bean中的FilterRegistrationBean注册Filter
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.springframework.boot.web.servlet;
import javax.servlet.Filter;
import org.springframework.boot.web.servlet.AbstractFilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.util.Assert;
public class FilterRegistrationBean extends AbstractFilterRegistrationBean {
public static final int REQUEST_WRAPPER_FILTER_MAX_ORDER = 0;
private Filter filter;
public FilterRegistrationBean() {
super(new ServletRegistrationBean[0]);
}
public FilterRegistrationBean(Filter filter, ServletRegistrationBean... servletRegistrationBeans) {
super(servletRegistrationBeans);
Assert.notNull(filter, "Filter must not be null");
this.filter = filter;
}
public Filter getFilter() {
return this.filter;
}
public void setFilter(Filter filter) {
Assert.notNull(filter, "Filter must not be null");
this.filter = filter;
}
}注册Filter
@Bean
public FilterRegistrationBean druidWebStatFilter() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());
//添加过滤规则.
filterRegistrationBean.addUrlPatterns("/*");
//添加不需要忽略的格式信息.
filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid2/*");
return filterRegistrationBean;
}转载请注明：码农博客 » Spring Boot过滤器Filter和Servlet注册