通过jndi连接自己的数据库,非全局配置,但一直报空指针异常,代码贴下来,请大神看看哪里错了
java代码,第一个是获取连接,第二个获取返回结果,代码运行在ps = conn.prepareStatement(sql)这里报异常,表名字没错,参数也没错,语句也没错,快奔溃了~
Context ctx = new InitialContext();
ds = (DataSource)ctx.lookup("java:com/env/mysqlDataSource");
return ds.getConnection();
PreparedStatement ps = null;
ResultSet rs = null;
if(conn==null){
conn = ConnectionInfoBean.getConnection();
}
String sql = "SELECT "+get+" FROM "+table;
System.out.println(sql);
try {
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
web.xml配置
<resource-ref>
<description>MySQL DB Connection</description>
<res-ref-name>mysqlDataSource</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
tomcat 配置,项目叫bynn ,所以在localhost的xml名叫bynn.xml,配置如下,名字和密码为安全起见没写
<?xml version="1.0" encoding="UTF-8"?>
<Context>
<Resource name="mysqlDataSource" auth="Container"
type="javax.sql.DataSource"
maxActive="100" maxIdle="10" maxWait="10000"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/bynn"
username="" password="" />
<WatchedResource>WEB-INF/web.xml</WatchedResource>
</Context>
问问题都不贴异常信息的?