【发布时间】：2012-08-05 13:24:27
【问题描述】：
我在我的eclipse项目中创建了一个derby Embedded Database，在eclipse上运行良好，但是将项目打包到Runnable jar文件时，连接数据库失败。
这是我的 Communicate.java
import java.io.File;
import java.security.NoSuchAlgorithmException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Communicate {
private static final String dbURL = "jdbc:derby:imagesDB;create=true";
private static final String tableName = "imageDB";
private static Connection conn = null;
private static Statement stmt = null;
public void insert(String path, String hash, long FileSize,
String label_name) throws NoSuchAlgorithmException, Exception {
try {
stmt = conn.createStatement();
stmt.execute("insert into " + tableName + " values (\'" + path
+ "\'," + FileSize + ",\'" + hash + "\'" + ",\'"
+ label_name + "\')");
stmt.close();
} catch (SQLException sqlExcept) {
sqlExcept.printStackTrace();
}
}
public void createConnection() {
try {
Class.forName("org.apache.derby.jdbc.EmbeddedDriver").newInstance();
// Get a connection
conn = DriverManager.getConnection(dbURL);
} catch (Exception except) {
except.printStackTrace();
}
}
public void createTable() throws SQLException {
Statement st = conn.createStatement();
st.execute("CREATE TABLE "
+ tableName
+ " (fullPath VARCHAR(512), fileSize INTEGER, md5 VARCHAR(512), label_name VARCHAR(100))");
}
public void indexTable() throws SQLException {
Statement st = conn.createStatement();
st.execute("CREATE INDEX imageDBIndex ON imageDB (fullPath, label_name)");
}
public void deleteTable() throws SQLException {
Statement st = conn.createStatement();
st.execute("drop table " + tableName);
}
public String searchBySizeAndMD(String file_path, long size, String hash)
throws SQLException {
StringBuilder sb = new StringBuilder();
Statement st = conn.createStatement();
ResultSet rs = st
.executeQuery("SELECT fullPath, label_name FROM (SELECT * FROM imageDB im WHERE im.fileSize = "
+ size + " ) as A WHERE A.md5 = " + "\'" + hash + "\'");
while (rs.next()) {
sb.append("Image: (" + rs.getString("fullPath")
+ ") is at label: (" + rs.getString("label_name") + ")\n");
}
return sb.toString();
}
public String searchByImageName(String fileName) throws SQLException {
StringBuilder sb = new StringBuilder();
Statement st = conn.createStatement();
ResultSet rs = st
.executeQuery("SELECT fullPath, label_name FROM imageDB im WHERE im.fullPath like \'%"
+ fileName + "%\'");
while (rs.next()) {
File out_path = new File(rs.getString("fullPath"));
if (!fileName.equals(out_path.getName())) continue;
sb.append("Image: (" + out_path.getPath()
+ ") is at label: (" + rs.getString("label_name") + ")\n");
}
return sb.toString();
}
public void deleteLabel(String label) throws SQLException {
Statement st = conn.createStatement();
st.execute("DELETE FROM " + tableName + " WHERE label_name = \'" + label + "\'");
}
}
对这个问题有帮助吗？
【问题讨论】：
-
您是要打包一个现有的数据库还是要在程序运行时创建一个新的数据库？
-
@Tichodroma 数据库已创建并嵌入到我的 Eclipse 项目中。
-
您使用
create=true，因此您应该在每次运行时获得一个新数据库。 -
导出 -> 可运行 Jar 文件 -> 选择我的主类 -> 选择我的输出 jar 路径 -> 勾选“将所需库打包到生成的 jar 中” -> ok
-
@Tichodroma 我已经删除了它，它修复了另一个错误，我在修复这个当前错误后会失败:(