在Android中使用Java代码下载网页可以使用HttpURLConnection或者OkHttp库。
使用HttpURLConnection:
```java
try {
URL url = new URL("http://www.example.com"); // 要下载的网页URL
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
// 下载成功
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
StringBuilder response = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
response.append(line);
}
br.close();
// 处理下载的网页内容
String html = response.toString();
// ...
} else {
// 下载失败
// ...
}
} catch (IOException e) {
e.printStackTrace();
}
```
使用OkHttp库:
首先要在项目的build.gradle文件中添加OkHttp的依赖:
```groovy
implementation 'com.squareup.okhttp3:okhttp:4.9.0'
```
然后编写下载网页的代码:
```java
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("http://www.example.com") // 要下载的网页URL
.build();
try {
Response response = client.newCall(request).execute();
if (response.isSuccessful()) {
// 下载成功
String html = response.body().string();
// 处理下载的网页内容
// ...
} else {
// 下载失败
// ...
}
} catch (IOException e) {
e.printStackTrace();
}
```
以上代码下载网页的内容后可以根据需要进行处理,比如解析HTML、保存到本地等。