五，手写SpringMVC框架，过滤器的使用

packagecom.hy.filter;

importjava.io.IOException;

importjavax.servlet.Filter;

importjavax.servlet.FilterChain;

importjavax.servlet.FilterConfig;

importjavax.servlet.ServletException;

importjavax.servlet.ServletRequest;

importjavax.servlet.ServletResponse;

importjavax.servlet.annotation.WebFilter;

importjavax.servlet.annotation.WebInitParam;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importcom.hy.utils.StringUtil;

@WebFilter(urlPatterns = { “*.do”},

initParams = {

@WebInitParam(name = “encoding”, value = “UTF-8”)

})

publicclassCharacterEncodingFilter implementsFilter {

privateString encoding= “UTF-8”;

@Override

publicvoidinit(FilterConfig filterConfig) throwsServletException {

String encoding= filterConfig.getInitParameter(“encoding”);

System.out.println(“encoding=”+encoding);

if(StringUtil.isNotEmpty(encoding)) {

this.encoding= encoding;

}

}

@Override

publicvoiddoFilter(ServletRequest req, ServletResponse resp, FilterChain chain)

throwsIOException, ServletException {

HttpServletRequest request= (HttpServletRequest) req;

HttpServletResponse response= (HttpServletResponse) resp;

request.setCharacterEncoding(encoding);

response.setCharacterEncoding(encoding);

response.setContentType(“text/html;charset=”+encoding);

chain.doFilter(request, response);

return;

}

@Override

publicvoiddestroy() {

}

}

createtableworker(

widintprimarykey,

wnamevarchar2(20),

ageint

)

select* fromuser_tables;

select* fromuser_col_commentswheretable_name= ‘WORKER’

select* fromworker;

insertintoworkervalues(1,’fbb’,10);

commit;

rollback;

##Oracle自动开启事务，但是需要手动的提交事务或回滚事务

##mysql默认自动开启事务，自动提交事务，失败自动回滚