java - 从文本文件解析 JSON 数据

Question

您好，我有 Java 类，它将从文件中读取和解析 JSON 数据并插入到数据库中，它们存储姓名、年龄和电话。该程序运行良好；但我的要求是，我有一个不同的 JSON 数据需要执行相同的操作，我想存储 AGE、ID 和 TYPE .我在上一部分提到了我的JSON数据

我从 https://javapages4all.wordpress.com/2012/12/10/read-from-json-file-and-persist-into-mysql/ 得到了这段代码

测试.json:

{'profiles':[
{'name':'Girish', 'age': 44, 'phone':'203-203-2030'},
{'name':'Alex','age':31, 'phone':'203-203-2030'},
{'name':'Amy', 'age': 24, 'phone':'203-203-2030'},
{'name':'Melissa','age':21, 'phone':'203-203-2030'}
]
}

Java 类:

package com.sample.json;


import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import org.apache.commons.io.IOUtils;

public class MyJson {
    private static String tableName = "jsontest";

    public static void main(String[] args) {
        try {
            ClassLoader cl = MyJson.class.getClassLoader();
            InputStream is = cl.getResourceAsStream("test.json");
            String str = IOUtils.toString(is);
            JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str);
            System.out.println(jsonObject);
            JSONArray jsonArr = jsonObject.getJSONArray("profiles");
            JSONObject obj = null;
            JSONArray nameArr = null;
            JSONArray valArr = null;

            for (int i = 0; i < jsonArr.size(); i++) {
                obj = jsonArr.getJSONObject(i);
                nameArr = obj.names();
                valArr = obj.toJSONArray(nameArr);
                //saveRecord(nameArr, valArr);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void saveRecord(JSONArray nameArray, JSONArray valArray) {
        Connection conn = getConnection();
        StringBuffer sb = new StringBuffer("insert into " + tableName + "(");
        int size = nameArray.size();
        int count = 0;
        Iterator<Object> iterator = nameArray.iterator();

        while (iterator.hasNext()) {
            if (count < (size - 1))
                sb.append(iterator.next() + ",");
            else
                sb.append(iterator.next() + ")");
            count++;
        }
        sb.append(" values(");

        for (int i = 0; i < size; i++) {
            if (i < (size - 1))
                sb.append("?,");
            else
                sb.append("?)");
        }
        System.out.println(sb.toString());
        try {
            PreparedStatement pstmt = conn.prepareStatement(sb.toString());
            bindVariables(valArray, pstmt);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private static void bindVariables(JSONArray valArray,
            PreparedStatement pstmt) throws SQLException {
        Iterator<Object> iterator = valArray.iterator();
        int cnt = 0;
        while (iterator.hasNext()) {
            Object obj = iterator.next();
            if (obj instanceof String) {
                pstmt.setString(++cnt, (String) obj);
            } else if (obj instanceof Integer) {
                pstmt.setLong(++cnt, (Integer) obj);
            } else if (obj instanceof Long) {
                pstmt.setLong(++cnt, (Long) obj);
            } else if (obj instanceof Double) {
                pstmt.setDouble(++cnt, (Double) obj);
            }
        }
    }

    private static Connection getConnection() {
        Connection con = null;
        String url = "jdbc:mysql://localhost:3306/";
        String db = "jsondata";
        String driver = "com.mysql.jdbc.Driver";
        String user = "root";
        String pass = "root";
        try {
            Class.forName(driver);
            con = DriverManager.getConnection(url + db, user, pass);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return con;
    }
}

我的 JSON:

[{"emp":{"age":34,"ID":3423423},"type":"s"}, 
{"emp":{"age":43,"ID":324324235},"type":"s"}, 
{"emp":{"age":36,"ID":324324236},"type":"v"},
{"emp":{"age":46,"ID":324324238},"type":"s"},
{"emp":{"age":55,"ID":324324243},"type":"s"},
{"emp":{"age":44,"ID":324324287},"type":"s"}]

对于上面的程序，我想使用这个 JSON 数据

Answer 1

我使用 Gson 为您的案例做了一个简单的示例来解析 json。

public class Result {
    private long id;
    private int age;
    private String type;

    public Result(long id, int age, String type) {
        this.age = age;
        this.id = id;
        this.type = type;
    }
}

public class EmployeeInfo {
    private int age;
    @SerializedName("ID")
    private long id;

    public EmployeeInfo(int age, long id) {
        this.age = age;
        this.id = id;
    }
}

public class Employee {
    @SerializedName("emp")
    private EmployeeInfo employeeInfo;
    private String type;

    public Employee(EmployeeInfo employeeInfo, String type) {
        this.employeeInfo = employeeInfo;
        this.type = type;
    }
}

运行:

public static void main(String[] args) throws IOException {
    String json = "[{\"emp\":{\"age\":34,\"ID\":3423423},\"type\":\"s\"}, \n" +
            "{\"emp\":{\"age\":43,\"ID\":324324235},\"type\":\"s\"}, \n" +
            "{\"emp\":{\"age\":36,\"ID\":324324236},\"type\":\"v\"},\n" +
            "{\"emp\":{\"age\":46,\"ID\":324324238},\"type\":\"s\"},\n" +
            "{\"emp\":{\"age\":55,\"ID\":324324243},\"type\":\"s\"},\n" +
            "{\"emp\":{\"age\":44,\"ID\":324324287},\"type\":\"s\"}]";

    Gson gson = new Gson();
    Type type = new TypeToken<List<Employee>>() {
    }.getType();
    List<Employee> employees = gson.fromJson(json, type);
    List<Result> results = new ArrayList<>();

    Result result;
    for (Employee employee : employees) {
        result = new Result(employee.getEmployeeInfo().getId(), employee.getEmployeeInfo().getAge(), employee.getType());

        results.add(result);
    }

    System.out.println(gson.toJson(results));

}