json封装与解析

最新推荐文章于 2020-11-11 16:35:41 发布

悠然Lucky

最新推荐文章于 2020-11-11 16:35:41 发布

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分类专栏： android 文章标签： gson 封装解析

本文链接：https://blog.youkuaiyun.com/wuyan2021/article/details/50732157

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本文展示了如何在Java服务器端使用Gson库封装数据为JSON格式，并通过HTTP响应发送给Android客户端。在Android端，使用Gson解析接收到的JSON字符串，将数据映射到对应的自定义类中，以便于访问和处理图片URL等信息。

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server端封装json：

protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("gbk");
response.setCharacterEncoding("gbk");
PrintWriter out= response.getWriter();
response.setContentType("text/html;charset=gbk");
System.out.println("doget");
String method=request.getParameter("method");

Map<String, Object> map = new HashMap<String, Object>();

if("selectUrl".equals(method)){

String mechid = request.getParameter("mechid");//获得从android端传过来的参数
Mechine mechine = iUser.selectUrl(mechid);//logo_picurl，background_picurl，AboutusUrl三张图地址

List<BigPic> bigpics = iUser.selectBig(mechid);
List<SmallPic> smallPics = iUser.selectSmall(mechid);
List<LunboPic> lunboPics = iUser.selectLunBo(mechid);

map = new HashMap<String, Object>();
map.put("logourl", mechine.getLogoUrl());
map.put("backurl", mechine.getBackUrl());
map.put("abouturl", mechine.getAboutusUrl());
map.put("bigs", bigpics);
map.put("smalls", smallPics);
map.put("lunbos", lunboPics);

JSONObject.fromObject(map).write(out);//把值封装成json格式
out.close();
out = null;
}

}

@Override
public Mechine selectUrl(String id) {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
//String logoUrl = null;
Mechine mechine = new Mechine();
try {
conn = JdbcUtils.getConnection();
String sql = "SELECT * FROM [VenMaDB_Iked].[dbo].[P_MachineInfo] WHERE id = ?";
ps = conn.prepareStatement(sql);
ps.setString(1,id);

rs = ps.executeQuery();
while(rs.next()){
mechine.setLogoUrl(rs.getString("logo_picurl"));
mechine.setBackUrl(rs.getString("background_picurl"));
mechine.setAboutusUrl(rs.getString("machineinfo"));

}

} catch (SQLException e) {

e.printStackTrace();
} catch (Exception e) {

e.printStackTrace();
} finally {
JdbcUtils.free(rs, ps, conn);
}
return mechine;
}

@Override
public List selectBig(String machineid) {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
//String logoUrl = null;
BigPic bigPic;
List<BigPic> bigPics = new ArrayList<BigPic>();
try {
conn = JdbcUtils.getConnection();
String sql = "SELECT * FROM [VenMaDB_Iked].[dbo].[P_MachineShowPic] WHERE machineid = ? and pictype='1'";
ps = conn.prepareStatement(sql);
ps.setString(1,machineid);
rs = ps.executeQuery();

while(rs.next()){
bigPic = new BigPic();
bigPic.setBigPic(rs.getString("picurl"));
bigPics.add(bigPic);
}

} catch (SQLException e) {

e.printStackTrace();
} catch (Exception e) {

e.printStackTrace();
} finally {
JdbcUtils.free(rs, ps, conn);
}
return bigPics;

}

public class Mechine {

private String logoUrl;
private String backUrl;
private String aboutusUrl;

public String getAboutusUrl() {
return aboutusUrl;
}
public void setAboutusUrl(String aboutusUrl) {
this.aboutusUrl = aboutusUrl;
}
public String getLogoUrl() {
return logoUrl;
}
public void setLogoUrl(String logoUrl) {
this.logoUrl = logoUrl;
}
public String getBackUrl() {
return backUrl;
}
public void setBackUrl(String backUrl) {
this.backUrl = backUrl;
}

}

public class BigPic {

private String bigPic;

public String getBigPic() {
return bigPic;
}

public void setBigPic(String bigPic) {
this.bigPic = bigPic;
}

}

public class SmallPic {
private String smallPic;

public String getSmallPic() {
return smallPic;
}

public void setSmallPic(String smallPic) {
this.smallPic = smallPic;
}

}

public class LunboPic {
private String LunboPic;

public String getLunboPic() {
return LunboPic;
}

public void setLunboPic(String lunboPic) {
LunboPic = lunboPic;
}
}

封装后数据：

{
"aboutusurl": "upload/img/machines/kedk0300000620160106/other/xxxx.jpg",
"logourl": "upload/img/machines/kedk0300000620160106/logo/1456131090372.jpg",
"smalls": [
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/6.jpg"
},
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/7.jpg"
},
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/8.jpg"
},
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/9.jpg"
},
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/4.jpg"
},
{
"smallPic": "upload/img/machines/kedk0300000620160106/small/5.jpg"
}
],
"lunbos": [
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/1.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/2.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/xxxx.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/3.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/4.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/5.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/6.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/XXXX.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/8.jpg"
},
{
"lunboPic": "upload/img/machines/kedk0300000620160106/base/9.jpg"
}
],
"bigs": [
{
"bigPic": "upload/img/machines/kedk0300000620160106/big/3.jpg"
},
{
"bigPic": "upload/img/machines/kedk0300000620160106/big/4.jpg"
},
{
"bigPic": "upload/img/machines/kedk0300000620160106/big/5.jpg"
}
],
"backurl": "upload/img/machines/kedk0300000620160106/background/1456131101602.jpg"
}

android端：

String url = "http://121.42.9.49/WeixinWbCs/AndroidServlet";
final Map<String, String> paras = new HashMap<String, String>();
paras.put("method","selectUrl");
paras.put("mechid","kedk0300000620160106");

String jsonString =HttpUtil.doPost(url, paras);
System.out.println("返回值是----"+jsonString);

if(jsonString!= null){
Gson gson=new Gson();
Mechine ked_pic=gson.fromJson(jsonString, Mechine.class);//所有的图片已经在ked_pic中，图片地址从ked_pic中取即可

System.out.println("aboutusurl:"+ked_pic.getAboutusurl());
System.out.println("BackUrl："+ked_pic.getBackurl());
System.out.println("LogoUrl："+ked_pic.getLogourl());

ArrayList<LunboPic> lists = ked_pic.getLunbos();
ArrayList<SmallPic> smallLists = ked_pic.getSmalls();
ArrayList<BigPic> bigLists = ked_pic.getBigs();
for(int i = 0;i < lists.size();i++){
String lunbo = lists.get(i).getLunboPic();//遍历list，lists.get(i)获得list的每个对象，.getLunboPic()取得每个对象的图片地址
System.out.println("轮播图pianyou："+lunbo);
}
for(int i = 0;i < smallLists.size();i++){
String small = smallLists.get(i).getSmallPic();
System.out.println("产品小图："+small);
}
for(int i = 0;i < bigLists.size();i++){
String big = bigLists.get(i).getBigPic();
System.out.println("产品大图："+big);
}
}

public class Mechine {

对应server端的Key
private String logourl;
private String backurl;
private String aboutusurl;
private ArrayList<LunboPic> lunbos;
private ArrayList<BigPic> bigs;
private ArrayList<SmallPic> smalls;//自动生成get和set方法，此处省略

}

public class LunboPic {
private String lunboPic;
//省略get与set方法
}

public class SmallPic {
private String smallPic;//对应数组

}

public class BigPic {
private String bigPic;

}

终于OK了！list取图片地址时候记得String lunbo = lists.get(i).getLunboPic();当时做的时候少些了getLunboPic()浪费了好多时间。

json封装 与 解析

json封装与解析