Question

了解我的Java技能人员。我曾经在Java里面用类声明我的连接细节。我这次决定尝试使用context和@Resource方法，并且遇到了一些错误

信息：服务器启动时间为1701毫秒 java.sql.SQLException：无法为连接URL' jdbc：oracle：thin @ // 10.30.30.30:1521/mydatabase?useSSL=false” at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createConnectionFactory（BasicDataSource.java:2065） at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createDataSource（BasicDataSource.java:1939） at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.getConnection（BasicDataSource.java:1412）在com.pldt.itms.FirstServlet.doGet（FirstServlet.java:40）在javax.servlet.http.HttpServlet.service（HttpServlet.java:618）在javax.servlet.http.HttpServlet.service（HttpServlet.java:725）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:291）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206）在org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:239）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206）在org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:219）在org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:106）在org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:501）在org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:142） at org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:79） at org.apache.catalina.valves.AbstractAccessLogValve.invoke（AbstractAccessLogValve.java:610）在org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:88）在org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:537）在org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1085） at org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:658）在org.apache.coyote.http11.Http11NioProtocol $ Http11ConnectionHandler.process（Http11NioProtocol.java:222）在org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.doRun（NioEndpoint.java:1556）在org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.run（NioEndpoint.java:1513） at java.util.concurrent.ThreadPoolExecutor.runWorker（Unknown Source） at java.util.concurrent.ThreadPoolExecutor $ Worker.run（Unknown Source） at org.apache.tomcat.util.threads.TaskThread $ WrappingRunnable.run（TaskThread.java:61）在java.lang.Thread.run（未知来源） 引起：java.sql.SQLException：没有合适的驱动程序 at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createConnectionFactory（BasicDataSource.java:2056） ......还有27个

下面是我在WebContent / META-INF
中的context.xml
<?xml version="1.0"?> <Context> <Resource url="jdbc:oracle:thin@//10.30.30.30:1521/mydatabase?useSSL=false" driverClassName="oracle.jdbc.driver.OracleDriver" password="password" username="username" maxWait="10000" maxIdle="5" maxActive="20" type="javax.sql.DataSource" auth="Container" name="jdbc/web_my_context"/> </Context>

这是我的Java类

package com.company.project; import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import javax.annotation.Resource; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.sql.DataSource; /** * Servlet implementation class FirstServlet */ @WebServlet("/FirstServlet") public class FirstServlet extends HttpServlet { private static final long serialVersionUID = 1L; @Resource(name="jdbc/web_my_context") DataSource dataSource; /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1 printwriter PrintWriter out = response.getWriter(); response.setContentType("text/plain"); //2 connect to db Connection myConn = null; Statement myStmt = null; ResultSet myRs = null; try{ myConn = dataSource.getConnection(); //3 create sql String sql = "select * from table_authorities"; myStmt = myConn.createStatement(); //4 execute sql myRs = myStmt.executeQuery(sql); //5 process resultset of sql statment while (myRs.next()){ String email = myRs.getString("username"); out.println(email); } } catch (Exception exc) { exc.printStackTrace(); } response.getWriter().append("Served at: ").append(request.getContextPath()); } }

修改我纠正了我的xml

<?xml version="1.0"?> <Context> <Resource url="jdbc:oracle:thin:@//10.30.30.30:1521/mydatabase?useSSL=false" driverClassName="oracle.jdbc.driver.OracleDriver" password="password" username="username" maxWait="10000" maxIdle="5" maxActive="20" type="javax.sql.DataSource" auth="Container" name="jdbc/web_my_context"/> </Context>

但现在它仍然是一个错误：

引起：oracle.net.ns.NetException：监听器拒绝连接出现以下错误：ORA-12514，TNS：当前没有侦听器知道连接描述符中请求的服务 oracle.net.ns.NSProtocolStream.negotiateConnection（NSProtocolStream.java:272）在oracle.net.ns.NSProtocol.connect（NSProtocol.java:263）at oracle.jdbc.driver.T4CConnection.connect（T4CConnection.java:1360）at at oracle.jdbc.driver.T4CConnection.logon（T4CConnection.java:486）... 35 更

Answer 1

正如其他人指出你的xml中存在语法错误，正确的语法是

def main():
    scores = input("Enter five test scores separated by commas: ")
    return [int(num) for num in scores.split(",")]


def determine_grade(num):
    if 90 <= num <= 100:
        letter_grade = "A"
    elif 80 <= num <= 89:
        letter_grade = "B"
    elif 70 <= num <= 79:
        letter_grade = "C"
    elif 60 <= num <= 69:
        letter_grade = "D"
    else:
        letter_grade = "F"
    return letter_grade


def calc_average(grades):
    average = sum(grades) / len(grades)
    grade = determine_grade(average)
    print("The average is: {:.1f} which is {}".format(average, grade))


def show_letters(num, letter_grade):
    print("{:.1f} is {}\n".format(num, letter_grade))


lst = main()
for n in lst:
    show_letters(n, determine_grade(n))
calc_average(lst)

我认为你只是在Oracle和MySQL之间切换时出错，我建议在发布问题时不这样做，这样我们就可以准确地帮助你，并且我们需要最新的语法。

更新回答

我认为造成错误的那个实际上就是这一行

＆＃39; JDBC：预言：薄@ // 10.30.30.30:1521/mydatabase?useSSL=false'

AFAIK useSSL = false 仅适用于MySQL，不适用于Oracle数据库。

尝试删除xml中的 useSSL = false 。您的代码现在应该如下所示

jdbc:oracle:thin:@//HOSTNAME:PORT/SERVICENAME

我认为默认情况下Oracle不使用SSL，您不再需要明确地说它不使用SSL。如果你想使用SSL for Oracle，你将不得不使用 tcps 协议，你可以使用像这样的长详细TNS样式。

'jdbc:oracle:thin@//10.30.30.30:1521/mydatabase'

如果您有兴趣配置Oracle连接以使用SSL，可以查看他们的documentation over at this LINK。

使用@Resource

1 个答案: