我写了下面这个Java程序
import java.io.*;
import java.util.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.*;
public class Sample {
public static void main (String[] args) throws IOException {
int CountComputers;
FileInputStream fstream = new FileInputStream(
"/export/hadoop-1.0.1/bin/countcomputers.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String result=br.readLine();
CountComputers=Integer.parseInt(result);
input.close();
fstream.close();
Connection con = null;
Statement st = null;
ResultSet rs = null;
String url = "jdbc:postgresql://192.168.1.8:5432/NexentaSearch";
String user = "postgres";
String password = "valter89";
ArrayList<String> paths = new ArrayList<String>();
try
{
con = DriverManager.getConnection(url, user, password);
st = con.createStatement();
rs = st.executeQuery("select path from tasks order by id");
while (rs.next()) { paths.add(rs.getString(1)); };
PrintWriter zzz = null;
try
{
zzz = new PrintWriter(new FileOutputStream("/export/hadoop-1.0.1/bin/readwaysfromdatabase.txt"));
}
catch(FileNotFoundException e)
{
System.out.println("Error");
System.exit(0);
}
for (int i=0; i<paths.size(); i++)
{
zzz.println("paths[i]=" + paths.get(i) + "\n");
}
zzz.close();
}
catch (SQLException e)
{
System.out.println("Connection Failed! Check output console");
e.printStackTrace();
}
}
}
我编译了这个程序并创建了jar文件
./javac -classpath /folder/postgresql-8.4-703.jdbc3.jar -d /Samplejavaprogram/classes /Samplejavaprogram/src/Sample.java
./jar -cvf /Samplejavaprogram/Sample.jar -C /Samplejavaprogram/classes/ .
Jar文件包含以下清单文件：
Manifest-Version: 1.0
Created-By: 1.7.0_06 (Oracle Corporation)
Main-Class: Sample
Class-Path: /folder/postgresql-8.4-703.jdbc3.jar
还包含文件/folder/postgresql-8.4-703.jdbc3.jar。我通过命令启动了Sample.jar
./java -jar -Djava.library.path=/opt/jdk1.7.0_06/lib /Samplejavaprogram/Sample.jar
因此我收到了以下信息：
Connection Failed! Check output console
java.sql.SQLException: No suitable driver found for jdbc:postgresql://192.168.1.8:5432/NexentaSearch
at java.sql.DriverManager.getConnection(DriverManager.java:604)
at java.sql.DriverManager.getConnection(DriverManager.java:221)
at org.myorg.Sample.main(Sample.java:33)
我从地址为192.168.1.10的主机上启动了文件，在地址为192.168.1.8的主机上它正常运行。请帮助消除一个错误。