Helper (GraphHopper API stable API)

java.lang.Object
- com.graphhopper.util.Helper

```
public class Helper
extends Object
```
Author:

Peter Karich

Field Summary

Fields
Modifier and Type	Field and Description
`static AngleCalc`	`ANGLE_CALC`
`static DistanceCalc`	`DIST_EARTH`
`static DistancePlaneProjection`	`DIST_PLANE`
`static long`	`MB`
`static TimeZone`	`UTC`
`static Charset`	`UTF_CS`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static int`	`calcIndexSize(BBox graphBounds)`
`static String`	`camelCaseToUnderScore(String key)`
`static void`	`close(Closeable cl)`
`static int`	`countBitValue(int maxTurnCosts)`
`static List<Double>`	`createDoubleList(double[] values)`
`static DateFormat`	`createFormatter()` This creates a date formatter for yyyy-MM-dd'T'HH:mm:ss'Z' which is has to be identical to buildDate used in pom.xml
`static DateFormat`	`createFormatter(String str)` Creates a SimpleDateFormat with the UK locale.
`static PointList`	`createPointList(double... list)`
`static PointList`	`createPointList3D(double... list)`
`static int`	`degreeToInt(double deg)` Converts into an integer to be compatible with the still limited DataAccess class (accepts only integer values).
`static int`	`eleToInt(double ele)` Converts elevation value (in meters) into integer for storage.
`static String`	`firstBig(String sayText)`
`static Locale`	`getLocale(String param)`
`static String`	`getMemInfo()`
`static int`	`getSizeOfLongArray(int length, int factor)`
`static int`	`getSizeOfObjectArray(int length, int factor)`
`static int`	`getSizeOfObjectRef(int factor)`
`static long`	`getTotalMB()`
`static long`	`getUsedMB()`
`static int`	`getUsedMBAfterGC()`
`static int`	`idealByteArraySize(int need)`
`static int`	`idealIntArraySize(int need)`
`static double`	`intToDegree(int storedInt)` Converts back the integer value.
`static double`	`intToEle(int integEle)` Converts the integer value retrieved from storage into elevation (in meters).
`static boolean`	`isEmpty(String str)`
`static boolean`	`isFileMapped(ByteBuffer bb)` Determines if the specified ByteBuffer is one which maps to a file!
`static String`	`isToString(InputStream inputStream)`
`static String`	`join(String delimiter, List<String> strings)` Equivalent to java 8 String#join
`static double`	`keepIn(double value, double min, double max)` This methods returns the value or min if too small or max if too big.
`static String`	`nf(long no)`
`static List<String>`	`parseList(String listStr)` parses a string like [a,b,c]
`static String`	`pruneFileEnd(String file)`
`static List<String>`	`readFile(Reader simpleReader)`
`static List<String>`	`readFile(String file)`
`static boolean`	`removeDir(File file)`
`static double`	`round(double value, int exponent)` Round the value to the specified exponent
`static double`	`round2(double value)`
`static double`	`round4(double value)`
`static double`	`round6(double value)`
`static void`	`saveProperties(Map<String,String> map, Writer tmpWriter)`
`static int`	`staticHashCode(String str)` Produces a static hashcode for a string that is platform independent and still compatible to the default of openjdk.
`static String`	`toLowerCase(String string)`
`static Object`	`toObject(String string)` This method probes the specified string for a boolean, int, long, float and double.
`static int`	`toSignedInt(long x)` Converts the specified long back into a signed int (reverse method for toUnsignedLong)
`static long`	`toUnsignedLong(int x)` This method handles the specified (potentially negative) int as unsigned bit representation and returns the positive converted long.
`static String`	`toUpperCase(String string)`
`static String`	`underScoreToCamelCase(String key)`

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

Field Detail

DIST_EARTH

public static final DistanceCalc DIST_EARTH

DIST_PLANE

public static final DistancePlaneProjection DIST_PLANE

ANGLE_CALC

public static final AngleCalc ANGLE_CALC

UTF_CS
```
public static final Charset UTF_CS
```

UTC
```
public static final TimeZone UTC
```

MB
```
public static final long MB
```
See Also:

Constant Field Values

Method Detail

getLocale

public static Locale getLocale(String param)

toLowerCase

public static String toLowerCase(String string)

toUpperCase

public static String toUpperCase(String string)

countBitValue

public static int countBitValue(int maxTurnCosts)

saveProperties

public static void saveProperties(Map<String,String> map,
                                  Writer tmpWriter)
                           throws IOException

Throws:: IOException

readFile

public static List<String> readFile(String file)
                             throws IOException

Throws:: IOException

readFile

public static List<String> readFile(Reader simpleReader)
                             throws IOException

Throws:: IOException

isToString

public static String isToString(InputStream inputStream)
                         throws IOException

Throws:: IOException

idealIntArraySize

public static int idealIntArraySize(int need)

idealByteArraySize

public static int idealByteArraySize(int need)

removeDir

public static boolean removeDir(File file)

getTotalMB
```
public static long getTotalMB()
```

getUsedMB
```
public static long getUsedMB()
```

getMemInfo
```
public static String getMemInfo()
```

getUsedMBAfterGC
```
public static int getUsedMBAfterGC()
```

getSizeOfObjectRef

public static int getSizeOfObjectRef(int factor)

getSizeOfLongArray

public static int getSizeOfLongArray(int length,
                                     int factor)

getSizeOfObjectArray

public static int getSizeOfObjectArray(int length,
                                       int factor)

close

public static void close(Closeable cl)

isEmpty

public static boolean isEmpty(String str)

isFileMapped
```
public static boolean isFileMapped(ByteBuffer bb)
```
Determines if the specified ByteBuffer is one which maps to a file!

calcIndexSize

public static int calcIndexSize(BBox graphBounds)

pruneFileEnd

public static String pruneFileEnd(String file)

createDoubleList

public static List<Double> createDoubleList(double[] values)

createPointList

public static PointList createPointList(double... list)

createPointList3D

public static PointList createPointList3D(double... list)

degreeToInt
```
public static int degreeToInt(double deg)
```
Converts into an integer to be compatible with the still limited DataAccess class (accepts only integer values). But this conversion also reduces memory consumption where the precision loss is acceptable. As +- 180° and +-90° are assumed as maximum values.

Returns:

the integer of the specified degree

intToDegree
```
public static double intToDegree(int storedInt)
```
Converts back the integer value.

Returns:

the degree value of the specified integer

eleToInt
```
public static int eleToInt(double ele)
```
Converts elevation value (in meters) into integer for storage.

intToEle
```
public static double intToEle(int integEle)
```
Converts the integer value retrieved from storage into elevation (in meters). Do not expect more precision than meters although it currently is!

nf
```
public static String nf(long no)
```

firstBig

public static String firstBig(String sayText)

keepIn

public static double keepIn(double value,
                            double min,
                            double max)

This methods returns the value or min if too small or max if too big.

round

public static double round(double value,
                           int exponent)

Round the value to the specified exponent

round6

public static double round6(double value)

round4

public static double round4(double value)

round2

public static double round2(double value)

createFormatter
```
public static DateFormat createFormatter()
```
This creates a date formatter for yyyy-MM-dd'T'HH:mm:ss'Z' which is has to be identical to buildDate used in pom.xml

createFormatter

public static DateFormat createFormatter(String str)

Creates a SimpleDateFormat with the UK locale.

toUnsignedLong
```
public static long toUnsignedLong(int x)
```
This method handles the specified (potentially negative) int as unsigned bit representation and returns the positive converted long.

toSignedInt
```
public static int toSignedInt(long x)
```
Converts the specified long back into a signed int (reverse method for toUnsignedLong)

toObject
```
public static Object toObject(String string)
```
This method probes the specified string for a boolean, int, long, float and double. If all this fails it returns the unchanged string.

camelCaseToUnderScore

public static String camelCaseToUnderScore(String key)

underScoreToCamelCase

public static String underScoreToCamelCase(String key)

join

public static String join(String delimiter,
                          List<String> strings)

Equivalent to java 8 String#join

parseList

public static List<String> parseList(String listStr)

parses a string like [a,b,c]

staticHashCode
```
public static int staticHashCode(String str)
```
Produces a static hashcode for a string that is platform independent and still compatible to the default of openjdk. Do not use for performance critical applications.

See Also:

String.hashCode()

Class Helper

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DIST_EARTH

DIST_PLANE

ANGLE_CALC

UTF_CS

UTC

MB

Method Detail

getLocale

toLowerCase

toUpperCase

countBitValue

saveProperties

readFile

readFile

isToString

idealIntArraySize

idealByteArraySize

removeDir

getTotalMB

getUsedMB

getMemInfo

getUsedMBAfterGC

getSizeOfObjectRef

getSizeOfLongArray

getSizeOfObjectArray

close

isEmpty

isFileMapped

calcIndexSize

pruneFileEnd

createDoubleList

createPointList

createPointList3D

degreeToInt

intToDegree

eleToInt

intToEle

nf

firstBig

keepIn

round

round6

round4

round2

createFormatter

createFormatter

toUnsignedLong

toSignedInt

toObject

camelCaseToUnderScore

underScoreToCamelCase

join

parseList

staticHashCode