Mysql Connector在JDK 1.7上不適用於Eclipse Juno

Question

我有一個Java程序，可以在MySQL數據庫上執行CRUD。

為此，我一直在使用：

Eclipse Indigo
Java 1.6
MySql-Connector-java-5.1.19-bin.jar

我嘗試在新機器上執行以下代碼：

Eclipse Juno
Java 1.7
MySql-Connector-java-5.1.19-bin.jar. 

我已經將MySql連接器添加到Eclipse Juno中的項目的Build Path中。

但是，ant構建失敗，並出現有關缺少類和軟件包的錯誤，這些錯誤應從連接器中獲取：

Buildfile: /home/rudra/Softwares/openfire/openfire_src/build/build.xml
init:
compile:
[javac] Compiling 14 source files to /home/rudra/Softwares/openfire/openfire_src/work/classes
[javac] warning: [options] bootstrap class path not set in conjunction with -source 1.5
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:3: error: package com.mysql.jdbc does not exist
[javac] import com.mysql.jdbc.Connection;
[javac]                      ^
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:4: error: package com.mysql.jdbc does not exist
[javac] import com.mysql.jdbc.PreparedStatement;
[javac]                      ^
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:5: error: package com.mysql.jdbc does not exist
[javac] import com.mysql.jdbc.ResultSet;
[javac]                      ^
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:21: error: cannot find symbol
[javac]             PreparedStatement stat = (PreparedStatement)connect.prepareStatement(query2);
[javac]             ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:21: error: cannot find symbol
[javac]             PreparedStatement stat = (PreparedStatement)connect.prepareStatement(query2);
[javac]                                       ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:21: error: cannot find symbol
[javac]             PreparedStatement stat = (PreparedStatement)connect.prepareStatement(query2);
[javac]                                                                ^
[javac]   symbol:   method prepareStatement(String)
[javac]   location: variable connect of type Connection
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:23: error: cannot find symbol
[javac]             ResultSet result = (ResultSet) stat.executeQuery();
[javac]             ^
[javac]   symbol:   class ResultSet
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:23: error: cannot find symbol
[javac]             ResultSet result = (ResultSet) stat.executeQuery();
[javac]                                 ^
[javac]   symbol:   class ResultSet
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:28: error: cannot find symbol
[javac]                 PreparedStatement preparedStmt = (PreparedStatement) connect.prepareStatement(query);
[javac]                 ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:28: error: cannot find symbol
[javac]                 PreparedStatement preparedStmt = (PreparedStatement) connect.prepareStatement(query);
[javac]                                                   ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:28: error: cannot find symbol
[javac]                 PreparedStatement preparedStmt = (PreparedStatement) connect.prepareStatement(query);
[javac]                                                                             ^
[javac]   symbol:   method prepareStatement(String)
[javac]   location: variable connect of type Connection
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:41: error: cannot find symbol
[javac]                 PreparedStatement statement = (PreparedStatement) connect.prepareStatement("Insert into user values (?,?,?);");
[javac]                 ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:41: error: cannot find symbol
[javac]                 PreparedStatement statement = (PreparedStatement) connect.prepareStatement("Insert into user values (?,?,?);");
[javac]                                                ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:41: error: cannot find symbol
[javac]                 PreparedStatement statement = (PreparedStatement) connect.prepareStatement("Insert into user values (?,?,?);");
[javac]                                                                          ^
[javac]   symbol:   method prepareStatement(String)
[javac]   location: variable connect of type Connection
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:73: error: cannot find symbol
[javac]             PreparedStatement statement = (PreparedStatement) connect.prepareStatement(query);
[javac]             ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:73: error: cannot find symbol
[javac]             PreparedStatement statement = (PreparedStatement) connect.prepareStatement(query);
[javac]                                            ^
[javac]   symbol:   class PreparedStatement
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:73: error: cannot find symbol
[javac]             PreparedStatement statement = (PreparedStatement) connect.prepareStatement(query);
[javac]                                                                      ^
[javac]   symbol:   method prepareStatement(String)
[javac]   location: variable connect of type Connection
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:75: error: cannot find symbol
[javac]             ResultSet result = (ResultSet) statement.executeQuery();
[javac]             ^
[javac]   symbol:   class ResultSet
[javac]   location: class UserDB
[javac] /home/rudra/Softwares/openfire/openfire_src/src/java/org/jivesoftware/openfire/UserDB.java:75: error: cannot find symbol
[javac]             ResultSet result = (ResultSet) statement.executeQuery();
[javac]                                 ^
[javac]   symbol:   class ResultSet
[javac]   location: class UserDB

誰能幫我這個？

Answer 1

從這個問題中得到啟示：

假設您在build.xml中有一個類似於以下內容的編譯目標：

<!-- Compile application -->
  <target name="compile">
    <mkdir dir="${classes.dir}"/>
    <javac srcdir="${src.dir}" destdir="${classes.dir}" debug="yes" includeantruntime="false">
      <classpath refid="classpath" />
    </javac>
  </target>

成功編譯所需的所有條件是定義類路徑，以使其包含項目的lib目錄中的所有jar，例如：

  <path id="classpath">
    <fileset dir="${lib.dir}" includes="*.jar"/>
  </path>

我從您的問題中了解到，您已經在Eclipse項目中添加了對連接器jar的引用。 將連接器jar復制到Eclipse項目的lib文件夾后，您可以嘗試上述建議。

另外，盡管我認為這不是一個很好的建議，但是您可以將項目導出為Ant Build並檢查由此生成的build.xml。 可以通過轉到文件->導出，鍵入'ant'進行過濾，然后選擇'Ant Buildfiles'來完成，如下所示：