play2.0文档-面向java开发者(3)

Manipulating the response 处理应答

Changing the default Content-Type 改变默认内容类型The result content type is automatically inferred from the Java value you specify as body.result的内容类型会根据你指定的java值自动推断出来For example:例如：

Result textResult = ok("Hello World!");

Will automatically set the

Content-Type

header to

text/plain

, while:这将会自动的设置内容类型为

text/plain

,而：

Result jsonResult = ok(jerksonObject);

will set the

Content-Type

header to

application/json

.将会设置内容类型为

application/json

.This is pretty useful, but sometimes you want to change it. Just use the

as(newContentType)

method on a result to create a new similiar result with a different

Content-Type

header:这是十分有用的，如果你想改变它，只需要调用

as(newContentType)

方法来创建一个新的result：

Result htmlResult = ok("<h1>Hello World!</h1>").as("text/html");

You can also set the content type on the HTTP response:你也可以设置HTTP应答的内容类型。

public static Result index() {

response().setContentType("text/html");

return ok("<h1>Hello World!</h1>");

}

Setting HTTP response headers 设置HTTP应答头

You can add (or update) any HTTP response header:你可以添加(或更新)任何HTTP应答头：

public static Result index() {

 response().setContentType("text/html");

response().setHeader(CACHE_CONTROL, "max-age=3600");

response().setHeader(ETAG, "xxx"); return ok("<h1>Hello World!</h1>");

}

Note that setting an HTTP header will automatically discard any previous value.注意 设置HTTP头会覆盖当前的值。

Setting and discarding cookies 设置和删除cookies

Cookies are just a special form of HTTP headers, but Play provides a set of helpers to make it easier.Cookies只不过是HTTP头的特定格式，但是play 提供了一系列便利方法：You can easily add a Cookie to the HTTP response:你可以很容易给HTTP应答添加一个Cookie：

response().setCookie("theme", "blue");

Also, to discard a Cookie previously stored on the Web browser:你也可以删除已有的Cookie：

response().discardCookies("theme");

Specifying the character encoding for text results

指定文本results 的字符编码

For a text-based HTTP response it is very important to handle the character encoding correctly. Play handles that for you and uses

utf-8

by default.正确的处理字符编码对于文本类型的HTTP应答是非常重要的，Play默认用

utf-8

.The encoding is used to both convert the text response to the corresponding bytes to send over the network socket, and to add the proper

;charset=xxx

extension to the

Content-Type

header.编码即用于把文本应答转换成相应的网络字节码，也为内容类型头添加恰当的

;charset=xxx

扩展The encoding can be specified when you are generating the

Result

value:你可以在生成

Result

值的时候指定编码：

public static Result index() {

response().setContentType("text/html; charset=iso-8859-1");

return ok("<h1>Hello World!</h1>", "iso-8859-1");

}