Question

我目前正在处理两个课程，即成分和成分服务。我没有编译Ingredient类的问题但我似乎无法编译另一个而不会在我尝试创建Ingredient对象的行中出现错误，即使它们位于相同的包/目录中。它们都位于：

C：\ progs的\ COM \ CS330 \

IngredientServices.java

package com.cs330;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.util.Arrays;

@Path("ws2")
public class IngredientServices {

@Path("/ingredients")
@GET
@Produces("text/plain")
public String getIngredients() throws SQLException, ClassNotFoundException {

    String connectStr="jdbc:mysql://localhost:3306/fooddb";
    String username="*****";
    String password="*****";
    String driver="com.mysql.jdbc.Driver";
    Class.forName(driver);

    Connection con = DriverManager.getConnection(connectStr, username, password);

    PreparedStatement preStatement = con.prepareStatement("SELECT id, name, category FROM ingredient");

    ResultSet rs= preStatement.executeQuery();

    Ingredient ing = new Ingredient();
    Ingredient[] ingArray = new Ingredient[100];
    int i=0;

    while (rs.next()) {
        ing = new Ingredient(rs.getInt("id"),rs.getString("name"),rs.getString("category"));
        ingArray[i] = ing;
        i++;
    }

    ingArray = Arrays.copyOf(ingArray,i);

return Arrays.toString(ingArray);
 }

成分类：

package com.cs330;

public class Ingredient {

private int id;
private String name;
private String category;

public Ingredient() {
id = 0;
name = null;
category = null;

}

public Ingredient(int id, String name, String category){
this.id = id;
this.name = name;
this.category = category;

}

public Ingredient(String name, String category){
id = 0;
this.name = name;
this.category = category;

}

  public String toString(){
    return (id + ": " + name + "( " + category + ") ");
}

}

使用javac进行编译时出现问题

0 个答案: