常用方法
- getJSONObject(String name) 获取JSONObject对象
- toString() 把JSONObject对象转换为json格式的字符串
class JSONActivity : AppCompatActivity() {
private var txt1: TextView? = null
private var txt2: TextView? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_json)
txt1 = findViewById(R.id.txt1)
txt2 = findViewById(R.id.txt2)
findViewById<View>(R.id.parse).setOnClickListener {
parseByJSONObject() }
}
private fun parseByJSONObject() {
object : Thread() {
override fun run() {
super.run()
val s = get()
//解析
try {
//参数：满足json格式要求的字符串
val jo = JSONObject(s)
val status = jo.getInt("status")
val msg = jo.getString("msg")
Log.e("TAG", "$status$msg===")
val data = jo.getJSONObject("data")
val title = data.getString("title")
//显示到界面上
//此方法在子线程中调用，可以在内部处理界面的显示问题
//因为它相当于在此刻将操作权由子线程移交给了主线程
runOnUiThread {
txt1!!.text = msg
txt2!!.text = title
}
} catch (e: JSONException) {
e.printStackTrace()
}
}
}.start()
}
fun get(): String? {
try {
//HttpURLConnection
//1.实例化一个URL对象
val url = URL("http://www.imooc.com/api/teacher?type=3&cid=1&type=3")
//2.获取HttpURLConnection实例
val conn = url.openConnection() as HttpURLConnection
//3.设置和请求相关的属性
//请求方式
conn.requestMethod = "GET"
//请求超时时长
conn.connectTimeout = 6000
//4.获取响应码
if (conn.responseCode == HttpURLConnection.HTTP_OK) {
//5.判断响应码并获取响应数据
//获取响应的流
val inputStream = conn.inputStream
val b = ByteArray(1024)
var len = 0
val baos = ByteArrayOutputStream()
//在循环中读取输入的流
//in.read(b); //该方法返回值是int类型数据，代表的是实际读到的数据长度
while (inputStream.read(b).also {
len = it } > -1) {
//将字节数组里面的内容存/写入缓存流
//参数1：待写入的数组
//参数2：起点
//参数3：长度
baos.write(b, 0, len)
}
val s = String(baos.toByteArray())
Log.e("TAG", "$s====")
return s
}
} catch (e: IOException) {
e.printStackTrace()
}
return null
}
}
解析JSONObject数组
class JSONActivity : AppCompatActivity() {
private var txt1: TextView? = null
private var txt2: TextView? = null
private var listView: ListView? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_json)
txt1 = findViewById(R.id.txt1)
txt2 = findViewById(R.id.txt2)
listView = findViewById(R.id.list_view)
findViewById<View>(R.id.parse).setOnClickListener {
parseByJSONObject() }
}
private fun parseByJSONObject() {
object : Thread() {
override fun run() {
super.run()
val s = get()
//解析
try {
//参数：满足json格式要求的字符串
val jo = JSONObject(s)
val status = jo.getInt("status")
val msg = jo.getString("msg")
Log.e("TAG", "$status$msg===")
// JSONObject data = jo.getJSONObject("data");
// final String title = data.getString("title");
//为ListMap准备数据源
val list: MutableList<Map<String, String?>> = ArrayList()
//解析JSON数组
val array = jo.getJSONArray("data")
for (i in 0 until array.length()) {
//取出对应索引上的JSON对象
val obj = array.getJSONObject(i)
val name = obj.getString("name")
val id = obj.getString("id")
Log.e("TAG", "id=$id, name=$name")
val map: MutableMap<String, String?> = HashMap()
map["name"] = name
map["id"] = id
list.add(map)
}
val from = arrayOf("name", "id")
val to = intArrayOf(R.id.item_name, R.id.item_id)
//创建SimpleAdapter
val adapter =
SimpleAdapter(this@JSONActivity, list, R.layout.item, from, to)
//显示到界面上
//此方法在子线程中调用，可以在内部处理界面的显示问题
//因为它相当于在此刻将操作权由子线程移交给了主线程
runOnUiThread {
listView!!.adapter = adapter }
} catch (e: JSONException) {
e.printStackTrace()
}
}
}.start()
}
fun get(): String? {
try {
//HttpURLConnection
//1.实例化一个URL对象
val url = URL("http://www.imooc.com/api/teacher?type=2&cid=1")
//2.获取HttpURLConnection实例
val conn = url.openConnection() as HttpURLConnection
//3.设置和请求相关的属性
//请求方式
conn.requestMethod = "GET"
//请求超时时长
conn.connectTimeout = 6000
//4.获取响应码
if (conn.responseCode == HttpURLConnection.HTTP_OK) {
//5.判断响应码并获取响应数据
//获取响应的流
val inputStream = conn.inputStream
val b = ByteArray(1024)
var len = 0
val baos = ByteArrayOutputStream()
//在循环中读取输入的流
//in.read(b); //该方法返回值是int类型数据，代表的是实际读到的数据长度
while (inputStream.read(b).also {
len = it } > -1) {
//将字节数组里面的内容存/写入缓存流
//参数1：待写入的数组
//参数2：起点
//参数3：长度
baos.write(b, 0, len)
}
val s = String(baos.toByteArray())
Log.e("TAG", "$s====")
return s
}
} catch (e: IOException) {
e.printStackTrace()
}
return null
}