jackson实现java对象转支付宝/微信模板消息

一、支付宝消息模板大致长这样

{
"to_user_id": "",
"telephone": "xxxxx",
"template": {
"template_id": "xxxxxx",
"context": {
"head_color": "#85be53",
"url": "www.baidu.com",
"action_name": "查看详情",
"keyword1": {
"color": "#85be53",
"value": "15700000000"
},
"keyword2": {
"color": "#85be53",
"value": "2017年06月"
},
"keyword3": {
"color": "#85be53",
"value": "99.99"
},
"keyword4": {
"color": "#85be53",
"value": "66.66"
},
"first": {
"color": "#85be53",
"value": "您好，本月账单已出"
},
"remark": {
"color": "#85be53",
"value": "谢谢使用。"
}
}
}
}

二、java pojo

Item实体 TemplateMessageItem.java

public class TemplateMessageItem {
private String value;
private String color;

public TemplateMessageItem(String value, String color) {
this.value = value;
this.color = color;
}

public TemplateMessageItem(String value) {
this.value = value;
this.color = "#113d83";
}

public String getValue() {
return this.value;
}

public void setValue(String value) {
this.value = value;
}

public String getColor() {
return this.color;
}

public void setColor(String color) {
this.color = color;
}
}

最外层：TemplateMessage .java

import com.fasterxml.jackson.annotation.JsonProperty;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

/**
* @author hujunzheng
* @create 2018-07-11 20:47
**/
public class TemplateMessage {
@JsonProperty("to_user_id")
private String toUserId = "";
private String telephone = "";
private NestTemplate template = new NestTemplate();

public String getToUserId() {
return toUserId;
}

public void setToUserId(String toUserId) {
this.toUserId = toUserId;
}

public String getTelephone() {
return telephone;
}

public void setTelephone(String telephone) {
this.telephone = telephone;
}

public NestTemplate getTemplate() {
return template;
}

public void setTemplate(NestTemplate template) {
this.template = template;
}

public TemplateMessage withToUserId(String toUserId) {
this.toUserId = toUserId;
return this;
}

public TemplateMessage withTelephone(String telephone) {
this.telephone = telephone;
return this;
}

public TemplateMessage withTemplateId(String templateId) {
this.template.setTemplateId(templateId);
return this;
}

public TemplateMessage withContextHeadColor(String color) {
this.template.getContext().setHeadColor(color);
return this;
}

public TemplateMessage withContextUrl(String url) {
this.template.getContext().setUrl(url);
return this;
}

public TemplateMessage withContextActionName(String actionName) {
this.getTemplate().getContext().setActionName(actionName);
return this;
}

public TemplateMessage withContextFirst(TemplateMessageItem first) {
this.getTemplate().getContext().setFirst(first);
return this;
}

public TemplateMessage withContextRemark(TemplateMessageItem remark) {
this.getTemplate().getContext().setRemark(remark);
return this;
}

public TemplateMessage addContextKeyword(TemplateMessageItem keyword) {
List<TemplateMessageItem> keywords = this.getTemplate().getContext().getKeywords();
if (Objects.isNull(keyword)) {
keywords = new ArrayList<>();
this.getTemplate().getContext().setKeywords(keywords);
}
keywords.add(keyword);
return this;
}
}

第一个嵌套层：NestTemplate.java

import com.fasterxml.jackson.annotation.JsonProperty;

public class NestTemplate {
@JsonProperty("template_id")
private String templateId;
private NestContext context = new NestContext();

public String getTemplateId() {
return templateId;
}

public void setTemplateId(String templateId) {
this.templateId = templateId;
}

public NestContext getContext() {
return context;
}

public void setContext(NestContext context) {
this.context = context;
}
}

第二个嵌套层：NestContext.java

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;

import java.util.List;

public class NestContext {
@JsonProperty("head_color")
private String headColor = "#85be53";
private String url;
@JsonProperty("action_name")
private String actionName;
private TemplateMessageItem first;
private TemplateMessageItem remark;

@JsonProperty("keyword1")
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonSerialize(using = TemplateMessageItemsSerializer.class)
private List<TemplateMessageItem> keywords;

public String getHeadColor() {
return headColor;
}

public void setHeadColor(String headColor) {
this.headColor = headColor;
}

public String getUrl() {
return url;
}

public void setUrl(String url) {
this.url = url;
}

public String getActionName() {
return actionName;
}

public void setActionName(String actionName) {
this.actionName = actionName;
}

public TemplateMessageItem getFirst() {
return first;
}

public void setFirst(TemplateMessageItem first) {
this.first = first;
}

public TemplateMessageItem getRemark() {
return remark;
}

public void setRemark(TemplateMessageItem remark) {
this.remark = remark;
}

public List<TemplateMessageItem> getKeywords() {
return keywords;
}

public void setKeywords(List<TemplateMessageItem> keywords) {
this.keywords = keywords;
}

public static void main(String[] args) throws JsonProcessingException {
NestContext context = new NestContext();
context.setFirst(new TemplateMessageItem("first"));
context.setRemark(new TemplateMessageItem("remark"));
context.setUrl("www.baidu.com");
context.setActionName("查看详情");
//        List<TemplateMessageItem> keywords = new ArrayList<>();
//        keywords.add(new TemplateMessageItem("充值金额"));
//        keywords.add(new TemplateMessageItem("手机号"));
//        context.setKeywords(keywords);
System.out.println(new ObjectMapper().writeValueAsString(context));
}
}

main方法中有注释：
{
    "url":"www.baidu.com",
    "first":{
        "value":"first",
        "color":"#113d83"
    },
    "remark":{
        "value":"remark",
        "color":"#113d83"
    },
    "head_color":"#85be53",
    "action_name":"查看详情"
}

main方法中无注释
{
    "url":"www.baidu.com",
    "first":{
        "value":"first",
        "color":"#113d83"
    },
    "remark":{
        "value":"remark",
        "color":"#113d83"
    },
    "head_color":"#85be53",
    "action_name":"查看详情",
    "keyword1":{
        "value":"充值金额",
        "color":"#113d83"
    },
    "keyword2":{
        "value":"手机号",
        "color":"#113d83"
    }
}

三、自定义字段序列化

　　将一个List中的每个对象输出为多个并列json key=value的形式，当然要靠JsonSerializer啦！

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.springframework.util.CollectionUtils;

import java.io.IOException;
import java.util.List;

/**
* @author hujunzheng
* @create 2018-07-11 21:30
**/
public class TemplateMessageItemsSerializer extends JsonSerializer<List<TemplateMessageItem>> {

@Override
public void serialize(List<TemplateMessageItem> items, JsonGenerator gen, SerializerProvider serializers) throws IOException, JsonProcessingException {
if (CollectionUtils.isEmpty(items)) {
return;
}

gen.writeObject(items.get(0));

for (int i = 1; i < items.size(); ++i) {
gen.writeFieldName("keyword" + (i + 1));
gen.writeObject(items.get(i));
}
}
}