Caller

java.lang.Object
- de.umass.lastfm.Caller

```
public class Caller
extends java.lang.Object
```
The Caller class handles the low-level communication between the client and last.fm.
Direct usage of this class should be unnecessary since all method calls are available via the methods in the Artist, Album, User, etc. classes. If specialized calls which are not covered by the Java API are necessary this class may be used directly.
Supports the setting of a custom Proxy and a custom User-Agent HTTP header.

Author:

Janni Kovacs

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Result`	`call(java.lang.String method, Session session, java.util.Map<java.lang.String,java.lang.String> params)`
`Result`	`call(java.lang.String method, Session session, java.lang.String... params)`
`Result`	`call(java.lang.String method, java.lang.String apiKey, java.util.Map<java.lang.String,java.lang.String> params)`
`Result`	`call(java.lang.String method, java.lang.String apiKey, java.lang.String... params)`
`Cache`	`getCache()` Returns the current `Cache`.
`static Caller`	`getInstance()` Returns the single instance of the `Caller` class.
`Result`	`getLastResult()` Returns the `Result` of the last operation, or `null` if no call operation has been performed yet.
`java.net.Proxy`	`getProxy()`
`java.lang.String`	`getUserAgent()`
`boolean`	`isDebugMode()`
`java.net.HttpURLConnection`	`openConnection(java.lang.String url)` Creates a new `HttpURLConnection`, sets the proxy, if available, and sets the User-Agent property.
`void`	`setApiRootUrl(java.lang.String apiRootUrl)` Set api root url.
`void`	`setCache(Cache cache)` Sets the active `Cache`.
`void`	`setDebugMode(boolean debugMode)` Sets the `debugMode` property.
`void`	`setProxy(java.net.Proxy proxy)` Sets a `Proxy` instance this Caller will use for all upcoming HTTP requests.
`void`	`setUserAgent(java.lang.String userAgent)` Sets a User Agent this Caller will use for all upcoming HTTP requests.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getInstance
```
public static Caller getInstance()
```
    Returns the single instance of the Caller class.
    
    Returns:
    
    a Caller
  - setApiRootUrl
```
public void setApiRootUrl(java.lang.String apiRootUrl)
```
    Set api root url.
    
    Parameters:
    
    apiRootUrl - new api root url
  - setProxy
```
public void setProxy(java.net.Proxy proxy)
```
    Sets a Proxy instance this Caller will use for all upcoming HTTP requests. May be null.
    
    Parameters:
    
    proxy - A Proxy or null.
  - setUserAgent
```
public void setUserAgent(java.lang.String userAgent)
```
    Sets a User Agent this Caller will use for all upcoming HTTP requests. For testing purposes use "tst". If you distribute your application use an identifiable User-Agent.
    
    Parameters:
    
    userAgent - a User-Agent string
  - setDebugMode
```
public void setDebugMode(boolean debugMode)
```
    Sets the debugMode property. If debugMode is true all call() methods will print debug information and error messages on failure to stdout and stderr respectively.
    Default is false. Set this to true while in development and for troubleshooting.
    
    Parameters:
    
    debugMode - true to enable debug mode
  - getCache
```
public Cache getCache()
```
    Returns the current Cache.
    
    Returns:
    
    the Cache
  - setCache
```
public void setCache(Cache cache)
```
    Sets the active Cache. May be null to disable caching.
    
    Parameters:
    
    cache - the new Cache or null
  - call
```
public Result call(java.lang.String method,
                   java.lang.String apiKey,
                   java.lang.String... params)
            throws CallException
```
    Throws:
    
    CallException
  - call
```
public Result call(java.lang.String method,
                   java.lang.String apiKey,
                   java.util.Map<java.lang.String,java.lang.String> params)
            throws CallException
```
    Throws:
    
    CallException
  - call
```
public Result call(java.lang.String method,
                   Session session,
                   java.lang.String... params)
```
  - call
```
public Result call(java.lang.String method,
                   Session session,
                   java.util.Map<java.lang.String,java.lang.String> params)
```
  - getLastResult
```
public Result getLastResult()
```
    Returns the Result of the last operation, or null if no call operation has been performed yet.
    
    Returns:
    
    the last Result object
  - openConnection
```
public java.net.HttpURLConnection openConnection(java.lang.String url)
                                          throws java.io.IOException
```
    Creates a new HttpURLConnection, sets the proxy, if available, and sets the User-Agent property.
    
    Parameters:
    
    url - URL to connect to
    
    Returns:
    
    a new connection.
    
    Throws:
    
    java.io.IOException - if an I/O exception occurs.
  - getProxy
```
public java.net.Proxy getProxy()
```
  - getUserAgent
```
public java.lang.String getUserAgent()
```
  - isDebugMode
```
public boolean isDebugMode()
```

Class Caller

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getInstance

setApiRootUrl

setProxy

setUserAgent

setDebugMode

getCache

setCache

call

call

call

call

getLastResult

openConnection

getProxy

getUserAgent

isDebugMode