DBMaker (mapdb 2.0-beta5 API)

java.lang.Object
- org.mapdb.DBMaker

```
public final class DBMaker
extends Object
```
A builder class to creare and open new database and individual collections. It has several static factory methods. Method names depends on type of storage it opens. DBMakeris typically used this way
```
  DB db = DBMaker
      .memoryDB()          //static method
      .transactionDisable()   //configuration option
      .make()                 //opens db
 
```
Author:

Jan Kotek

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

protected static interface DBMaker.Keys

static class DBMaker.Maker

Nested Classes
Modifier and Type	Class and Description
`protected static interface`	`DBMaker.Keys`
`static class`	`DBMaker.Maker`

Field Summary

Fields
Modifier and Type Field and Description

protected static Logger LOG

protected static String TRUE

Fields
Modifier and Type	Field and Description
`protected static Logger`	`LOG`
`protected static String`	`TRUE`

Constructor Summary

Constructors
Constructor and Description

DBMaker()

Constructors
Constructor and Description
`DBMaker()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static DBMaker.Maker`	`appendFileDB(File file)` Creates or open append-only database stored in file.
`static DBMaker.Maker`	`fileDB(File file)` Creates or open database stored in file.
`static DB.HTreeMapMaker`	`hashMapSegmented(DBMaker.Maker maker)`
`static DB.HTreeMapMaker`	`hashMapSegmentedMemory()`
`static DB.HTreeMapMaker`	`hashMapSegmentedMemoryDirect()`
`static DBMaker.Maker`	`heapDB()` Creates new in-memory database which stores all data on heap without serialization.
`static DBMaker.Maker`	`memoryDB()` Creates new in-memory database.
`static DBMaker.Maker`	`memoryDirectDB()` Creates new in-memory database.
`static DBMaker.Maker`	`memoryUnsafeDB()` Creates new in-memory database.
`static DBMaker.Maker`	`newAppendFileDB(File file)` Deprecated. method renamed, prefix removed, use `appendFileDB(File)`
`static <K,V> HTreeMap<K,V>`	`newCache(double size)` Deprecated. TODO this method is going to be replaced by something
`static <K,V> HTreeMap<K,V>`	`newCacheDirect(double size)` Deprecated. TODO this method is going to be replaced by something
`static DBMaker.Maker`	`newFileDB(File file)` Deprecated. method renamed, prefix removed, use `fileDB(File)`
`static DBMaker.Maker`	`newHeapDB()` Deprecated. method renamed, prefix removed, use `heapDB()`
`static DBMaker.Maker`	`newMemoryDB()` Deprecated. method renamed, prefix removed, use `memoryDB()`
`static DBMaker.Maker`	`newMemoryDirectDB()` Deprecated. method renamed, prefix removed, use `memoryDirectDB()`
`static DBMaker.Maker`	`newMemoryUnsafeDB()` Deprecated. method renamed, prefix removed, use `memoryUnsafeDB()`
`static DBMaker.Maker`	`newTempFileDB()` Deprecated. method renamed, prefix removed, use `tempFileDB()`
`static <K,V> HTreeMap<K,V>`	`newTempHashMap()` Deprecated. method renamed, prefix removed, use `tempHashMap()`
`static <K> Set<K>`	`newTempHashSet()` Deprecated. method renamed, prefix removed, use `tempHashSet()`
`static <K,V> BTreeMap<K,V>`	`newTempTreeMap()` Deprecated. method renamed, prefix removed, use `tempTreeMap()`
`static <K> NavigableSet<K>`	`newTempTreeSet()` Deprecated. method renamed, prefix removed, use `tempTreeSet()`
`static DBMaker.Maker`	`tempFileDB()` Creates new database in temporary folder.
`static <K,V> HTreeMap<K,V>`	`tempHashMap()` Create new HTreeMap backed by temporary file storage.
`static <K> Set<K>`	`tempHashSet()` Create new HashSet backed by temporary file storage.
`static <K,V> BTreeMap<K,V>`	`tempTreeMap()` Create new BTreeMap backed by temporary file storage.
`static <K> NavigableSet<K>`	`tempTreeSet()` Create new TreeSet backed by temporary file storage.

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

- Field Detail
  - LOG
```
protected static final Logger LOG
```
  - TRUE
```
protected static final String TRUE
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - DBMaker
```
public DBMaker()
```
- Method Detail
  - heapDB
```
public static DBMaker.Maker heapDB()
```
    Creates new in-memory database which stores all data on heap without serialization. This mode should be very fast, but data will affect Garbage Collector the same way as traditional Java Collections.
  - newHeapDB
```
public static DBMaker.Maker newHeapDB()
```
    Deprecated. method renamed, prefix removed, use heapDB()
  - memoryDB
```
public static DBMaker.Maker memoryDB()
```
    Creates new in-memory database. Changes are lost after JVM exits. This option serializes data into byte[], so they are not affected by Garbage Collector.
  - newMemoryDB
```
public static DBMaker.Maker newMemoryDB()
```
    Deprecated. method renamed, prefix removed, use memoryDB()
  - memoryDirectDB
```
public static DBMaker.Maker memoryDirectDB()
```
    Creates new in-memory database. Changes are lost after JVM exits.
    This will use DirectByteBuffer outside of HEAP, so Garbage Collector is not affected You should increase ammount of direct memory with -XX:MaxDirectMemorySize=10G JVM param
  - newMemoryDirectDB
```
public static DBMaker.Maker newMemoryDirectDB()
```
    Deprecated. method renamed, prefix removed, use memoryDirectDB()
  - memoryUnsafeDB
```
public static DBMaker.Maker memoryUnsafeDB()
```
    Creates new in-memory database. Changes are lost after JVM exits.
    This will use sun.misc.Unsafe. It uses direct-memory access and avoids boundary checking. It is bit faster compared to DirectByteBuffer, but can cause JVM crash in case of error.
    If sun.misc.Unsafe is not available for some reason, MapDB will log an warning and fallback into DirectByteBuffer based in-memory store without throwing an exception.
  - newMemoryUnsafeDB
```
public static DBMaker.Maker newMemoryUnsafeDB()
```
    Deprecated. method renamed, prefix removed, use memoryUnsafeDB()
  - appendFileDB
```
public static DBMaker.Maker appendFileDB(File file)
```
    Creates or open append-only database stored in file. This database uses format other than usual file db
    
    Parameters:
    
    file -
    
    Returns:
    
    maker
  - newAppendFileDB
```
public static DBMaker.Maker newAppendFileDB(File file)
```
    Deprecated. method renamed, prefix removed, use appendFileDB(File)
  - tempTreeMap
```
public static <K,V> BTreeMap<K,V> tempTreeMap()
```
    Create new BTreeMap backed by temporary file storage. This is quick way to create 'throw away' collection.
    Storage is created in temp folder and deleted on JVM shutdown
  - newTempTreeMap
```
public static <K,V> BTreeMap<K,V> newTempTreeMap()
```
    Deprecated. method renamed, prefix removed, use tempTreeMap()
  - tempHashMap
```
public static <K,V> HTreeMap<K,V> tempHashMap()
```
    Create new HTreeMap backed by temporary file storage. This is quick way to create 'throw away' collection.
    Storage is created in temp folder and deleted on JVM shutdown
  - newTempHashMap
```
public static <K,V> HTreeMap<K,V> newTempHashMap()
```
    Deprecated. method renamed, prefix removed, use tempHashMap()
  - tempTreeSet
```
public static <K> NavigableSet<K> tempTreeSet()
```
    Create new TreeSet backed by temporary file storage. This is quick way to create 'throw away' collection.
    Storage is created in temp folder and deleted on JVM shutdown
  - newTempTreeSet
```
public static <K> NavigableSet<K> newTempTreeSet()
```
    Deprecated. method renamed, prefix removed, use tempTreeSet()
  - tempHashSet
```
public static <K> Set<K> tempHashSet()
```
    Create new HashSet backed by temporary file storage. This is quick way to create 'throw away' collection.
    Storage is created in temp folder and deleted on JVM shutdown
  - newTempHashSet
```
public static <K> Set<K> newTempHashSet()
```
    Deprecated. method renamed, prefix removed, use tempHashSet()
  - tempFileDB
```
public static DBMaker.Maker tempFileDB()
```
    Creates new database in temporary folder.
  - newTempFileDB
```
public static DBMaker.Maker newTempFileDB()
```
    Deprecated. method renamed, prefix removed, use tempFileDB()
  - newCacheDirect
```
public static <K,V> HTreeMap<K,V> newCacheDirect(double size)
```
    Deprecated. TODO this method is going to be replaced by something
    
    Creates new off-heap cache with maximal size in GBs. Entries are removed from cache in most-recently-used fashion if store becomes too big. This method uses off-heap direct ByteBuffers. See ByteBuffer.allocateDirect(int)
    
    Parameters:
    
    size - maximal size of off-heap store in gigabytes.
    
    Returns:
    
    map
  - newCache
```
public static <K,V> HTreeMap<K,V> newCache(double size)
```
    Deprecated. TODO this method is going to be replaced by something
    
    Creates new cache with maximal size in GBs. Entries are removed from cache in most-recently-used fashion if store becomes too big. This cache uses on-heap byte[], but does not affect GC since objects are serialized into binary form. This method uses ByteBuffers backed by on-heap byte[]. See ByteBuffer.allocate(int)
    
    Parameters:
    
    size - maximal size of off-heap store in gigabytes.
    
    Returns:
    
    map
  - fileDB
```
public static DBMaker.Maker fileDB(File file)
```
    Creates or open database stored in file.
  - newFileDB
```
public static DBMaker.Maker newFileDB(File file)
```
    Deprecated. method renamed, prefix removed, use fileDB(File)
  - hashMapSegmented
```
public static DB.HTreeMapMaker hashMapSegmented(DBMaker.Maker maker)
```
  - hashMapSegmentedMemory
```
public static DB.HTreeMapMaker hashMapSegmentedMemory()
```
  - hashMapSegmentedMemoryDirect
```
public static DB.HTreeMapMaker hashMapSegmentedMemoryDirect()
```

Class DBMaker

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

TRUE

Constructor Detail

DBMaker

Method Detail

heapDB

newHeapDB

memoryDB

newMemoryDB

memoryDirectDB

newMemoryDirectDB

memoryUnsafeDB

newMemoryUnsafeDB

appendFileDB

newAppendFileDB

tempTreeMap

newTempTreeMap

tempHashMap

newTempHashMap

tempTreeSet

newTempTreeSet

tempHashSet

newTempHashSet

tempFileDB

newTempFileDB

newCacheDirect

newCache

fileDB

newFileDB

hashMapSegmented

hashMapSegmentedMemory

hashMapSegmentedMemoryDirect