java 获取request中json数据

叁歲伎倆 2023-09-26 19:15 13阅读 0赞

**功能简介：**

Java 从 HttpServletRequest 中获取前端传输过来的json数据

**效果展示：**

![ac36202f3b4c4eba91bc91d37e251503.png][]

**请求示例：**

post: 127.0.0.1:8081/getRequestJson

{"messageHistory",[{"message":"123","time":"2023-03-22 10:00:00"}],"isContextChat":true}

**代码示例：**

@RequestMapping(value = "getRequestJson", method = RequestMethod.POST)
    @ResponseBody
    public String getRequestJson(HttpServletRequest request) throws IOException {
        StringBuilder buffer = new StringBuilder();
        BufferedReader reader = request.getReader();
        String line;
        while ((line = reader.readLine()) != null) {
            buffer.append(line);
        }
        String requestBody = buffer.toString();
        System.out.println("--------> get request json is :" + requestBody);
    	return requestBody;
    }

拓展：

import com.fasterxml.jackson.databind.JsonNode;
    import com.fasterxml.jackson.databind.ObjectMapper;
    
    @RequestMapping(value = "getRequestJson", method = RequestMethod.POST)
    @ResponseBody
    public String getRequestJson(HttpServletRequest request) throws IOException {
    
    	// 1. 从HttpServletRequest对象中获取输入流，并读取请求正文。
    	StringBuilder buffer = new StringBuilder();
    	BufferedReader reader = request.getReader();
    	String line;
    	while ((line = reader.readLine()) != null) {
    		buffer.append(line);
    	}
    	String requestBody = buffer.toString();
    
    	// 2. 使用JSON库（如Jackson、Gson等）将字符串解析为JsonNode或任何其他适合你的数据结构。
    	ObjectMapper mapper = new ObjectMapper(); // Jackson JSON库示例
    	JsonNode jsonNode = mapper.readTree(requestBody); // 解析为JsonNode对象
    
    	// 3. 现在，你可以使用jsonNode对象来访问和操作JSON数据了。
    	String name = jsonNode.get("name").asText();
    	int age = jsonNode.get("age").asInt();
    	// 遍历所有属性并打印它们的值：
    	Iterator<String> fieldNamesIter= jsonNode.fieldNames();
    	while (fieldNamesIter.hasNext()){
    		String fieldName=fieldNamesIter.next();
    		JsonNode fieldValue=jsonNode.get(fieldName);
    		System.out.println(fieldName+": "+fieldValue.asText());
    	}
    
    	System.out.println("--------> get request json is :" + requestBody);
    	return requestBody;
    }

[ac36202f3b4c4eba91bc91d37e251503.png]: https://img-blog.csdnimg.cn/ac36202f3b4c4eba91bc91d37e251503.png