for (int i = 0; i < strings.size(); i++) { strings.set(i, strings.get(i).toUpperCase()); }

您的代码中有一个错误。在 for 循环中，变量 i 的递增部分被省略了，应该写成 i++ 或者 i+=1，否则代码会陷入死循环。修改后的代码如下：

for (int i = 0; i < strings.size(); i++) {
strings.set(i, strings.get(i).toUpperCase());
}

相关问题

c语言 检查一下下面的代码 为什么函数中获取不到键值#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/socket.h> #include <arpa/inet.h> #include <openssl/ssl.h> #include <openssl/err.h> #include <openssl/hmac.h> #include <jansson.h> #include <time.h> #include <errno.h> #include <resolv.h> #include <netdb.h> char* calculate_signature(char* json_str, char* key) { json_t *root; json_error_t error; /* 从文件中读取 JSON 数据 */ root = json_load_file(json_str, 0, &error); /* 遍历 JSON 对象中的所有键值对，并获取键的名称 */ int key_count = json_object_size(root); printf("key_names %d\n", key_count); const char *key_name; json_t *value; const char **key_names = (const char **)malloc(key_count * sizeof(char *)); int i = 0; json_object_foreach(root, key_name, value) { key_name = json_object_iter_key(value); key_names[i] = key_name; i++; } printf("key_names %s\n", key_names[2]); //int str_num = i; // 计算字符串数组中的字符串数量 /* char **sorted_names = sort_strings(key_names, key_count); char* stringA = (char*)malloc(1); // 初始化为一个空字符串 stringA[0] = '\0'; size_t len = 0; for (int i = 0; i < str_num; i++) { char* key = sorted_names[i]; json_t* value = json_object_get(root, key); char* str = json_dumps(value, JSON_ENCODE_ANY | JSON_COMPACT); len += strlen(key) + strlen(str) + 2; // 2 是键值对之间的字符 stringA = (char*)realloc(stringA, len); strcat(stringA, key); strcat(stringA, "="); strcat(stringA, str); strcat(stringA, "&"); free(str); } free(sorted_names); stringA[strlen(stringA) - 1] = '\0'; // 去掉最后一个"&" printf("stringA%s\n", stringA); unsigned char* sign = (unsigned char*)malloc(EVP_MAX_MD_SIZE); unsigned int sign_len = 0; HMAC(EVP_sha256(), key, strlen(key), (unsigned char*)stringA, strlen(stringA), sign, &sign_len); // 计算HMAC-SHA256签名 char* signature = (char*)malloc(sign_len * 2 + 1); // 签名的十六进制表示 signature[0] = '\0'; // 初始化为一个空字符串 for (int i = 0; i < sign_len; i++) { sprintf(signature + i * 2, "%02x", sign[i]); } json_object_set_new(root, "sign", json_string(signature)); // 在json中添加"sign"参数 json_dumpf(root, stdout, JSON_ENCODE_ANY | JSON_COMPACT); // 输出带有"sign"参数的json字符串 json_decref(root); free(key_names); free(stringA); free(sign); printf("signature%s\n", signature); */ return("A"); } int main() { char *key="39cabdfaab8c4da09bd6e9823c527836"; char *sss="{\"timestamp\":1685509898,\"sdkVersion\":\"1.0.30_1\",\"vin\":\"LJUBMSA24PKFFF198\"}"; calculate_signature(sss, key) ; }

代码中的问题在于 `json_load_file` 函数的第一个参数应该是一个文件名字符串，而不是 JSON 字符串。因此，需要将 `calculate_signature` 函数中的第一个参数 `json_str` 修改为文件名。

修改后的代码如下：

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/hmac.h>
#include <jansson.h>
#include <time.h>
#include <errno.h>
#include <resolv.h>
#include <netdb.h>

char* calculate_signature(char* filename, char* key) {
    json_t *root;
    json_error_t error;
    /* 从文件中读取 JSON 数据 */
    root = json_load_file(filename, 0, &error);
    if (!root) {
        printf("Error in %s line %d: %s\n", error.source, error.line, error.text);
        return NULL;
    }

    /* 遍历 JSON 对象中的所有键值对，并获取键的名称 */
    int key_count = json_object_size(root);
    printf("key_names %d\n", key_count);
    const char *key_name;
    json_t *value;
    const char **key_names = (const char **)malloc(key_count * sizeof(char *));
    int i = 0;
    json_object_foreach(root, key_name, value) {
        key_name = json_object_iter_key(value);
        key_names[i] = key_name;
        i++;
    }
    printf("key_names %s\n", key_names[2]);

    //int str_num = i; // 计算字符串数组中的字符串数量
    /*
    char **sorted_names = sort_strings(key_names, key_count);
    char* stringA = (char*)malloc(1); // 初始化为一个空字符串
    stringA[0] = '\0';
    size_t len = 0;
    for (int i = 0; i < str_num; i++) {
        char* key = sorted_names[i];
        json_t* value = json_object_get(root, key);
        char* str = json_dumps(value, JSON_ENCODE_ANY | JSON_COMPACT);
        len += strlen(key) + strlen(str) + 2; // 2 是键值对之间的字符
        stringA = (char*)realloc(stringA, len);
        strcat(stringA, key);
        strcat(stringA, "=");
        strcat(stringA, str);
        strcat(stringA, "&");
        free(str);
    }
    free(sorted_names);
    stringA[strlen(stringA) - 1] = '\0'; // 去掉最后一个"&"

    printf("stringA%s\n", stringA);

    unsigned char* sign = (unsigned char*)malloc(EVP_MAX_MD_SIZE);
    unsigned int sign_len = 0;
    HMAC(EVP_sha256(), key, strlen(key), (unsigned char*)stringA, strlen(stringA), sign, &sign_len); // 计算HMAC-SHA256签名

    char* signature = (char*)malloc(sign_len * 2 + 1); // 签名的十六进制表示
    signature[0] = '\0'; // 初始化为一个空字符串
    for (int i = 0; i < sign_len; i++) {
        sprintf(signature + i * 2, "%02x", sign[i]);
    }

    json_object_set_new(root, "sign", json_string(signature)); // 在json中添加"sign"参数
    json_dumpf(root, stdout, JSON_ENCODE_ANY | JSON_COMPACT); // 输出带有"sign"参数的json字符串
    json_decref(root);
    free(key_names);
    free(stringA);
    free(sign);

    printf("signature%s\n", signature);

    */

    return("A");
}

int main() {
    char *key="39cabdfaab8c4da09bd6e9823c527836";
    char *filename="test.json";
    calculate_signature(filename, key) ;
    return 0;
}

另外，代码中还有一些注释掉的部分，需要先实现对应的函数才能使用。

public class InterfaceCallExample extends JFrame implements ActionListener { private static final long serialVersionUID = 1L; private JButton callButton; private JTable resultTable; private DefaultTableModel tableModel; public InterfaceCallExample() { super("Interface Call Example"); setSize(400, 300); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel panel = new JPanel(); callButton = new JButton("查看数据"); callButton.addActionListener(this); panel.add(callButton); add(panel, BorderLayout.NORTH); tableModel = new DefaultTableModel(); tableModel.addColumn("id"); tableModel.addColumn("材料类型"); tableModel.addColumn("状态"); tableModel.addColumn("创建时间"); tableModel.addColumn("更改时间"); resultTable = new JTable(tableModel); add(new JScrollPane(resultTable), BorderLayout.CENTER); } public static void main(String[] args) { InterfaceCallExample example = new InterfaceCallExample(); example.setVisible(true); } @Override public void actionPerformed(ActionEvent e) { if (e.getSource() == callButton) { try { URL url = new URL("http://101.34.120.182:8081/wnapp/productType/getTypeId?category=1&status=0&type="); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream())); String s = reader.readLine(); JSONObject jsonObject = new JSONObject(); JSONObject object = JSONObject.parseObject(s); Object o = object.get("data"); JSONObject object1 = JSONObject.parseObject(o.toString()); ArrayList<Map<String,Object>> list = (ArrayList<Map<String,Object>>) object1.get("list"); for (Map<String,Object> map : list){ String id = map.get("id").toString(); String titleName = map.get("titleName").toString(); String status = map.get("status").toString(); String createTime = map.get("createTime").toString(); String updateTime = map.get("updateTime").toString(); ArrayList<String> strings = new ArrayList<>(); strings.add(id); strings.add(titleName); strings.add(status); strings.add(createTime); strings.add(updateTime); String[] data = strings.toString().replace("[","").replace("]","").split(","); tableModel.addRow(data); } reader.close(); } catch (Exception ex) { ex.printStackTrace(); } } } } 将以上代码获取的每条数据后面添加删除和修改的按钮

可以在表格中添加一个新的列，用于显示每一行的“删除”和“修改”按钮。每当添加一行数据时，就在该列中添加对应的按钮。以下是修改后的代码：

public class InterfaceCallExample extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JButton callButton;
    private JTable resultTable;
    private DefaultTableModel tableModel;
    private JButton[] editButtons; // 修改按钮
    private JButton[] deleteButtons; // 删除按钮

    public InterfaceCallExample() {
        super("Interface Call Example");
        setSize(500, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        callButton = new JButton("查看数据");
        callButton.addActionListener(this);
        panel.add(callButton);
        add(panel, BorderLayout.NORTH);
        tableModel = new DefaultTableModel();
        tableModel.addColumn("id");
        tableModel.addColumn("材料类型");
        tableModel.addColumn("状态");
        tableModel.addColumn("创建时间");
        tableModel.addColumn("更改时间");
        tableModel.addColumn("操作"); // 操作列
        resultTable = new JTable(tableModel);
        add(new JScrollPane(resultTable), BorderLayout.CENTER);
    }

    public static void main(String[] args) {
        InterfaceCallExample example = new InterfaceCallExample();
        example.setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == callButton) {
            try {
                URL url = new URL("http://101.34.120.182:8081/wnapp/productType/getTypeId?category=1&status=0&type=");
                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("GET");
                BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                String s = reader.readLine();
                JSONObject jsonObject = new JSONObject();
                JSONObject object = JSONObject.parseObject(s);
                Object o = object.get("data");
                JSONObject object1 = JSONObject.parseObject(o.toString());
                ArrayList<Map<String,Object>> list = (ArrayList<Map<String,Object>>) object1.get("list");

                int rowCount = tableModel.getRowCount();
                for (int i = 0; i < rowCount; i++) {
                    tableModel.removeRow(0);
                }
                editButtons = new JButton[list.size()];
                deleteButtons = new JButton[list.size()];
                for (int i = 0; i < list.size(); i++) {
                    Map<String,Object> map = list.get(i);
                    String id = map.get("id").toString();
                    String titleName = map.get("titleName").toString();
                    String status = map.get("status").toString();
                    String createTime = map.get("createTime").toString();
                    String updateTime = map.get("updateTime").toString();
                    ArrayList<String> strings = new ArrayList<String>();
                    strings.add(id);
                    strings.add(titleName);
                    strings.add(status);
                    strings.add(createTime);
                    strings.add(updateTime);
                    String[] data = strings.toString().replace("[","").replace("]","").split(",");
                    tableModel.addRow(data);

                    // 添加修改按钮
                    editButtons[i] = new JButton("修改");
                    editButtons[i].addActionListener(new EditButtonActionListener(tableModel, i));
                    resultTable.setValueAt(editButtons[i], i, 5);

                    // 添加删除按钮
                    deleteButtons[i] = new JButton("删除");
                    deleteButtons[i].addActionListener(new DeleteButtonActionListener(tableModel, i));
                    resultTable.setValueAt(deleteButtons[i], i, 6);
                }
                reader.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }

    // 修改按钮事件处理器
    private class EditButtonActionListener implements ActionListener {
        private DefaultTableModel tableModel;
        private int row;

        public EditButtonActionListener(DefaultTableModel tableModel, int row) {
            this.tableModel = tableModel;
            this.row = row;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO: 实现修改操作
            System.out.println("修改第" + row + "行数据");
        }
    }

    // 删除按钮事件处理器
    private class DeleteButtonActionListener implements ActionListener {
        private DefaultTableModel tableModel;
        private int row;

        public DeleteButtonActionListener(DefaultTableModel tableModel, int row) {
            this.tableModel = tableModel;
            this.row = row;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            tableModel.removeRow(row);
        }
    }
}

在上述代码中，我们添加了两个内部类 `EditButtonActionListener` 和 `DeleteButtonActionListener`，分别用于处理“修改”和“删除”按钮的事件。在 `actionPerformed` 方法中，我们将每一行的“修改”和“删除”按钮添加到表格中，同时为每个按钮添加相应的事件处理器。当用户单击“修改”或“删除”按钮时，相应的事件处理器会被触发，从而实现对数据的修改或删除。