com.mysql.cj.util

Class Util

java.lang.Object

com.mysql.cj.util.Util

public class Util
extends java.lang.Object

Various utility methods for the driver.

Constructor Summary

Constructors

Constructor and Description
Util()

Method Summary

Modifier and Type	Method and Description
static java.util.Map<java.lang.Object,java.lang.Object>	calculateDifferences(java.util.Map<?,?> map1, java.util.Map<?,?> map2)
static java.lang.Class<?>[]	getImplementedInterfaces(java.lang.Class<?> clazz) Retrieves a list with all interfaces implemented by the given class.
static java.lang.Object	getInstance(java.lang.String className, java.lang.Class<?>[] argTypes, java.lang.Object[] args, ExceptionInterceptor exceptionInterceptor)
static java.lang.Object	getInstance(java.lang.String className, java.lang.Class<?>[] argTypes, java.lang.Object[] args, ExceptionInterceptor exceptionInterceptor, java.lang.String errorMessage)
static int	getJVMUpdateNumber()
static int	getJVMVersion()
static java.lang.String	getPackageName(java.lang.Class<?> clazz) Returns the package name of the given class.
static java.lang.Object	handleNewInstance(java.lang.reflect.Constructor<?> ctor, java.lang.Object[] args, ExceptionInterceptor exceptionInterceptor) Handles constructing new instance with the given constructor and wrapping (or not, as required) the exceptions that could possibly be generated
static boolean	interfaceExists(java.lang.String hostname) Does a network interface exist locally with the given hostname?
static boolean	isCommunityEdition(java.lang.String serverVersion) Checks whether the given server version string is a MySQL Community edition
static boolean	isEnterpriseEdition(java.lang.String serverVersion) Checks whether the given server version string is a MySQL Enterprise edition
static boolean	isJdbcInterface(java.lang.Class<?> clazz) Recursively checks for interfaces on the given class to determine if it implements a java.sql, javax.sql or com.mysql.cj.jdbc interface.
static boolean	isJdbcPackage(java.lang.String packageName) Check if the package name is a known JDBC package.
static boolean	isNullOrEmpty(java.util.List<?> list)
static boolean	isRunningOnWindows() Checks if the JVM is running on Windows Operating System.
static boolean	jvmMeetsMinimum(int version, int updateNumber)
static <T> java.util.List<T>	loadClasses(java.lang.String extensionClassNames, java.lang.String errorMessageKey, ExceptionInterceptor exceptionInterceptor)
static int	readBlock(java.io.InputStream i, byte[] b, ExceptionInterceptor exceptionInterceptor)
static int	readBlock(java.io.InputStream i, byte[] b, int length, ExceptionInterceptor exceptionInterceptor)
static int	readFully(java.io.Reader reader, char[] buf, int length) Reads length bytes from reader into buf.
static long	secondsSinceMillis(long timeInMillis) Computes the number of seconds elapsed since the given time in milliseconds.
static java.lang.String	stackTraceToString(java.lang.Throwable ex) Converts a nested exception into a nicer message
static int	truncateAndConvertToInt(long longValue) Converts long to int, truncating to maximum/minimum value if needed.
static int[]	truncateAndConvertToInt(long[] longArray) Converts long[] to int[], truncating to maximum/minimum value if needed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Util

public Util()

Method Detail

getJVMVersion

public static int getJVMVersion()

jvmMeetsMinimum

public static boolean jvmMeetsMinimum(int version,
                                      int updateNumber)

getJVMUpdateNumber

public static int getJVMUpdateNumber()

isCommunityEdition

public static boolean isCommunityEdition(java.lang.String serverVersion)

Checks whether the given server version string is a MySQL Community edition

Parameters:

serverVersion - full server version string

Returns:

true if version does not contain "enterprise", "commercial" or "advanced"

isEnterpriseEdition

public static boolean isEnterpriseEdition(java.lang.String serverVersion)

Checks whether the given server version string is a MySQL Enterprise edition

Parameters:

serverVersion - full server version string

Returns:

true if version contains "enterprise", "commercial" or "advanced"

stackTraceToString

public static java.lang.String stackTraceToString(java.lang.Throwable ex)

Converts a nested exception into a nicer message

Parameters:

ex - the exception to expand into a message.

Returns:

a message containing the exception, the message (if any), and a stacktrace.

getInstance

public static java.lang.Object getInstance(java.lang.String className,
                                           java.lang.Class<?>[] argTypes,
                                           java.lang.Object[] args,
                                           ExceptionInterceptor exceptionInterceptor,
                                           java.lang.String errorMessage)

getInstance

public static java.lang.Object getInstance(java.lang.String className,
                                           java.lang.Class<?>[] argTypes,
                                           java.lang.Object[] args,
                                           ExceptionInterceptor exceptionInterceptor)

handleNewInstance

public static java.lang.Object handleNewInstance(java.lang.reflect.Constructor<?> ctor,
                                                 java.lang.Object[] args,
                                                 ExceptionInterceptor exceptionInterceptor)

Handles constructing new instance with the given constructor and wrapping (or not, as required) the exceptions that could possibly be generated

Parameters:

ctor - constructor

args - arguments for constructor

exceptionInterceptor - exception interceptor

Returns:

object

interfaceExists

public static boolean interfaceExists(java.lang.String hostname)

Does a network interface exist locally with the given hostname?

Parameters:

hostname - the hostname (or IP address in string form) to check

Returns:

true if it exists, false if no, or unable to determine due to VM version support of java.net.NetworkInterface

calculateDifferences

public static java.util.Map<java.lang.Object,java.lang.Object> calculateDifferences(java.util.Map<?,?> map1,
                                                                                    java.util.Map<?,?> map2)

loadClasses

public static <T> java.util.List<T> loadClasses(java.lang.String extensionClassNames,
                                                java.lang.String errorMessageKey,
                                                ExceptionInterceptor exceptionInterceptor)

isJdbcInterface

public static boolean isJdbcInterface(java.lang.Class<?> clazz)

Recursively checks for interfaces on the given class to determine if it implements a java.sql, javax.sql or com.mysql.cj.jdbc interface.

Parameters:

clazz - The class to investigate.

Returns:

boolean

isJdbcPackage

public static boolean isJdbcPackage(java.lang.String packageName)

Check if the package name is a known JDBC package.

Parameters:

packageName - The package name to check.

Returns:

boolean

getImplementedInterfaces

public static java.lang.Class<?>[] getImplementedInterfaces(java.lang.Class<?> clazz)

Retrieves a list with all interfaces implemented by the given class. If possible gets this information from a cache instead of navigating through the object hierarchy. Results are stored in a cache for future reference.

Parameters:

clazz - The class from which the interface list will be retrieved.

Returns:

An array with all the interfaces for the given class.

secondsSinceMillis

public static long secondsSinceMillis(long timeInMillis)

Computes the number of seconds elapsed since the given time in milliseconds.

Parameters:

timeInMillis - The past instant in milliseconds.

Returns:

The number of seconds, truncated, elapsed since timeInMillis.

truncateAndConvertToInt

public static int truncateAndConvertToInt(long longValue)

Converts long to int, truncating to maximum/minimum value if needed.

Parameters:

longValue - long value

Returns:

int value

truncateAndConvertToInt

public static int[] truncateAndConvertToInt(long[] longArray)

Converts long[] to int[], truncating to maximum/minimum value if needed.

Parameters:

longArray - log values

Returns:

int values

getPackageName

public static java.lang.String getPackageName(java.lang.Class<?> clazz)

Returns the package name of the given class. Using clazz.getPackage().getName() is not an alternative because under some class loaders the method getPackage() just returns null.

Parameters:

clazz - the Class from which to get the package name

Returns:

the package name

isRunningOnWindows

public static boolean isRunningOnWindows()

Checks if the JVM is running on Windows Operating System.

Returns:

true if currently running on Windows, false otherwise.

readFully

public static int readFully(java.io.Reader reader,
                            char[] buf,
                            int length)
                     throws java.io.IOException

Reads length bytes from reader into buf. Blocks until enough input is available

Parameters:

reader - Reader

buf - char array to read into

length - number of chars to read

Returns:

the actual number of chars read

Throws:

java.io.IOException - if an error occurs

readBlock

public static final int readBlock(java.io.InputStream i,
                                  byte[] b,
                                  ExceptionInterceptor exceptionInterceptor)

readBlock

public static final int readBlock(java.io.InputStream i,
                                  byte[] b,
                                  int length,
                                  ExceptionInterceptor exceptionInterceptor)

isNullOrEmpty

public static boolean isNullOrEmpty(java.util.List<?> list)