Android 性能优化（10）网络优化（ 6）Optimizing General Network Use

Optimizing General Network Use

This lesson teaches you to

1. Compress Data
2. Cache Files Locally
3. Optimize Pre-Fetch Cache Size

　　In general, reducing the amount of network traffic helps reduce battery drain. In addition to the battery-optimization techniques of the previous lessons, you should look at these general-purpose techniques and see if you can apply them to your app.

　　This lesson briefly covers techniques that you can use to lower network traffic and consequently reduce the battery drain caused by your app.

Compress Data

　　https://youtu.be/IwxIIUypnTE

　　Reducing the amount of data sent or received over a network connection also reduces the duration of the connection, which conserves battery. You can:

• Compress data, using a compression technique such as GZIP compression.
• Use succinct data protocols. While JSON and XML offer human-readability, and language-flexibility, they are bandwidth-heavy formats, with high serialization costs in the Android platform. Binary serialization formats, such as Protocol Buffers or FlatBuffers offer a smaller on-the-wire packet size, as well as faster encoding and decoding time. If your application transfers a lot of serialized data on a regular basis, these formats can yield benefits for decoding time and transfer size.

Cache Files Locally

　　https://youtu.be/7lxVqqWwTb0

　　Your app can avoid downloading duplicate data by caching. Always cache static resources, including on-demand downloads such as full size images, and cache them for as long as reasonably possible.

　　For example, you should consider this approach for a networked app that displays data from user-initiated network requests as the primary content on the screen. When the user opens this screen the first time, the app should display a splash screen. Subsequent loads should initially load with the data that was cached from the last network request. The screen reloads with new data once the network request is complete.

　　To learn about caching, watch the video. To implement caching in your app, see Cache Files Locally.

Optimize Pre-Fetch Cache Size

　　Optimize pre-fetch cache size based on local file system size and current network connectivity. You can use the connectivity manager to determine what type of networks (Wi-FI, LTE, HSPAP, EDGE, GPRS) are active and modify your pre-fetching routines to minimize battery load.

　　For more information, see Use Modifying your Download Patterns Based on the Connectivity Type.