SystemUtil (hutool-码云(gitee.com))

java.lang.Object
- cn.hutool.system.SystemUtil

```
public class SystemUtil
extends Object
```
Java的System类封装工具类。
参考：http://blog.csdn.net/zhongweijian/article/details/7619383

Author:

Looly

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CLASS_PATH` Java 类路径的KEY
`static String`	`CLASS_VERSION` Java 类格式版本号的KEY
`static String`	`COMPILER` 要使用的 JIT 编译器的名称的KEY
`static String`	`EXT_DIRS` 一个或多个扩展目录的路径的KEY
`static String`	`FILE_SEPARATOR` 文件分隔符（在 UNIX 系统中是“/”）的KEY
`static String`	`HOME` Java 安装目录的KEY
`static String`	`LIBRARY_PATH` 加载库时搜索的路径列表的KEY
`static String`	`LINE_SEPARATOR` 行分隔符（在 UNIX 系统中是“\n”）的KEY
`static String`	`OS_ARCH` 操作系统的架构的KEY
`static String`	`OS_NAME` 操作系统的名称的KEY
`static String`	`OS_VERSION` 操作系统的版本的KEY
`static String`	`PATH_SEPARATOR` 路径分隔符（在 UNIX 系统中是“:”）的KEY
`static String`	`SPECIFICATION_NAME` Java 运行时环境规范名称的KEY
`static String`	`SPECIFICATION_VENDOR` Java 运行时环境规范供应商的KEY
`static String`	`SPECIFICATION_VERSION` Java 运行时环境规范版本的KEY
`static String`	`TMPDIR` 默认的临时文件路径的KEY
`static String`	`USER_DIR` 用户的当前工作目录的KEY
`static String`	`USER_HOME` 用户的主目录的KEY
`static String`	`USER_NAME` 用户的账户名称的KEY
`static String`	`VENDOR` Java 运行时环境供应商的KEY
`static String`	`VENDOR_URL` Java 供应商的 URL的KEY
`static String`	`VERSION` Java 运行时环境版本的KEY
`static String`	`VM_NAME` Java 虚拟机实现名称的KEY
`static String`	`VM_SPECIFICATION_NAME` Java 虚拟机规范名称的KEY
`static String`	`VM_SPECIFICATION_VENDOR` Java 虚拟机规范供应商的KEY
`static String`	`VM_SPECIFICATION_VERSION` Java 虚拟机规范版本的KEY
`static String`	`VM_VENDOR` Java 虚拟机实现供应商的KEY
`static String`	`VM_VERSION` Java 虚拟机实现版本的KEY

Constructor Summary

Constructors
Constructor and Description

SystemUtil()

Constructors
Constructor and Description
`SystemUtil()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`protected static void`	`append(StringBuilder builder, String caption, Object value)` 输出到`StringBuilder`。
`static void`	`dumpSystemInfo()` 将系统信息输出到`System.out`中。
`static void`	`dumpSystemInfo(PrintWriter out)` 将系统信息输出到指定`PrintWriter`中。
`static String`	`get(String key)` 获得System属性
`static String`	`get(String name, boolean quiet)` 取得系统属性，如果因为Java安全的限制而失败，则将错误打在Log中，然后返回 `null`
`static String`	`get(String name, String defaultValue)` 取得系统属性，如果因为Java安全的限制而失败，则将错误打在Log中，然后返回 defaultValue
`static boolean`	`getBoolean(String key, boolean defaultValue)` 获得boolean类型值
`static ClassLoadingMXBean`	`getClassLoadingMXBean()` 返回Java虚拟机类加载系统相关属性
`static CompilationMXBean`	`getCompilationMXBean()` 返回Java虚拟机编译系统相关属性如果没有编译系统，则返回`null`
`static long`	`getCurrentPID()` 获取当前进程 PID
`static long`	`getFreeMemory()` 获取JVM中内存剩余大小
`static List<GarbageCollectorMXBean>`	`getGarbageCollectorMXBeans()` 获取Java虚拟机中的`GarbageCollectorMXBean`列表
`static HostInfo`	`getHostInfo()` 取得Host的信息。
`static long`	`getInt(String key, int defaultValue)` 获得int类型值
`static JavaInfo`	`getJavaInfo()` 取得Java Implementation的信息。
`static JavaRuntimeInfo`	`getJavaRuntimeInfo()` 取得当前运行的JRE的信息。
`static JavaSpecInfo`	`getJavaSpecInfo()` 取得Java Specification的信息。
`static JvmInfo`	`getJvmInfo()` 取得Java Virtual Machine Implementation的信息。
`static JvmSpecInfo`	`getJvmSpecInfo()` 取得Java Virtual Machine Specification的信息。
`static long`	`getLong(String key, long defaultValue)` 获得long类型值
`static long`	`getMaxMemory()` 获取JVM可用的内存总大小
`static List<MemoryManagerMXBean>`	`getMemoryManagerMXBeans()` 获取Java虚拟机中的`MemoryManagerMXBean`列表 The Java virtual machine can have one or more memory managers.
`static MemoryMXBean`	`getMemoryMXBean()` 返回Java虚拟机内存系统相关属性
`static List<MemoryPoolMXBean>`	`getMemoryPoolMXBeans()` 获取Java虚拟机中的`MemoryPoolMXBean`列表 The Java virtual machine can have one or more memory pools.
`static OperatingSystemMXBean`	`getOperatingSystemMXBean()` 返回Java虚拟机运行下的操作系统相关信息属性
`static OsInfo`	`getOsInfo()` 取得OS的信息。
`static RuntimeInfo`	`getRuntimeInfo()` 取得Runtime的信息。
`static RuntimeMXBean`	`getRuntimeMXBean()` 返回Java虚拟机运行时系统相关属性
`static ThreadMXBean`	`getThreadMXBean()` 返回Java虚拟机线程系统相关属性
`static long`	`getTotalMemory()` 获取JVM中内存总大小
`static int`	`getTotalThreadCount()` 获取总线程数
`static UserInfo`	`getUserInfo()` 取得User的信息。
`static Properties`	`props()`

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

- Field Detail
  - SPECIFICATION_NAME
```
public static final String SPECIFICATION_NAME
```
    Java 运行时环境规范名称的KEY
    
    See Also:
    
    Constant Field Values
  - VERSION
```
public static final String VERSION
```
    Java 运行时环境版本的KEY
    
    See Also:
    
    Constant Field Values
  - SPECIFICATION_VERSION
```
public static final String SPECIFICATION_VERSION
```
    Java 运行时环境规范版本的KEY
    
    See Also:
    
    Constant Field Values
  - VENDOR
```
public static final String VENDOR
```
    Java 运行时环境供应商的KEY
    
    See Also:
    
    Constant Field Values
  - SPECIFICATION_VENDOR
```
public static final String SPECIFICATION_VENDOR
```
    Java 运行时环境规范供应商的KEY
    
    See Also:
    
    Constant Field Values
  - VENDOR_URL
```
public static final String VENDOR_URL
```
    Java 供应商的 URL的KEY
    
    See Also:
    
    Constant Field Values
  - HOME
```
public static final String HOME
```
    Java 安装目录的KEY
    
    See Also:
    
    Constant Field Values
  - LIBRARY_PATH
```
public static final String LIBRARY_PATH
```
    加载库时搜索的路径列表的KEY
    
    See Also:
    
    Constant Field Values
  - TMPDIR
```
public static final String TMPDIR
```
    默认的临时文件路径的KEY
    
    See Also:
    
    Constant Field Values
  - COMPILER
```
public static final String COMPILER
```
    要使用的 JIT 编译器的名称的KEY
    
    See Also:
    
    Constant Field Values
  - EXT_DIRS
```
public static final String EXT_DIRS
```
    一个或多个扩展目录的路径的KEY
    
    See Also:
    
    Constant Field Values
  - VM_NAME
```
public static final String VM_NAME
```
    Java 虚拟机实现名称的KEY
    
    See Also:
    
    Constant Field Values
  - VM_SPECIFICATION_NAME
```
public static final String VM_SPECIFICATION_NAME
```
    Java 虚拟机规范名称的KEY
    
    See Also:
    
    Constant Field Values
  - VM_VERSION
```
public static final String VM_VERSION
```
    Java 虚拟机实现版本的KEY
    
    See Also:
    
    Constant Field Values
  - VM_SPECIFICATION_VERSION
```
public static final String VM_SPECIFICATION_VERSION
```
    Java 虚拟机规范版本的KEY
    
    See Also:
    
    Constant Field Values
  - VM_VENDOR
```
public static final String VM_VENDOR
```
    Java 虚拟机实现供应商的KEY
    
    See Also:
    
    Constant Field Values
  - VM_SPECIFICATION_VENDOR
```
public static final String VM_SPECIFICATION_VENDOR
```
    Java 虚拟机规范供应商的KEY
    
    See Also:
    
    Constant Field Values
  - CLASS_VERSION
```
public static final String CLASS_VERSION
```
    Java 类格式版本号的KEY
    
    See Also:
    
    Constant Field Values
  - CLASS_PATH
```
public static final String CLASS_PATH
```
    Java 类路径的KEY
    
    See Also:
    
    Constant Field Values
  - OS_NAME
```
public static final String OS_NAME
```
    操作系统的名称的KEY
    
    See Also:
    
    Constant Field Values
  - OS_ARCH
```
public static final String OS_ARCH
```
    操作系统的架构的KEY
    
    See Also:
    
    Constant Field Values
  - OS_VERSION
```
public static final String OS_VERSION
```
    操作系统的版本的KEY
    
    See Also:
    
    Constant Field Values
  - FILE_SEPARATOR
```
public static final String FILE_SEPARATOR
```
    文件分隔符（在 UNIX 系统中是“/”）的KEY
    
    See Also:
    
    Constant Field Values
  - PATH_SEPARATOR
```
public static final String PATH_SEPARATOR
```
    路径分隔符（在 UNIX 系统中是“:”）的KEY
    
    See Also:
    
    Constant Field Values
  - LINE_SEPARATOR
```
public static final String LINE_SEPARATOR
```
    行分隔符（在 UNIX 系统中是“\n”）的KEY
    
    See Also:
    
    Constant Field Values
  - USER_NAME
```
public static final String USER_NAME
```
    用户的账户名称的KEY
    
    See Also:
    
    Constant Field Values
  - USER_HOME
```
public static final String USER_HOME
```
    用户的主目录的KEY
    
    See Also:
    
    Constant Field Values
  - USER_DIR
```
public static final String USER_DIR
```
    用户的当前工作目录的KEY
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SystemUtil
```
public SystemUtil()
```
- Method Detail
  - get
```
public static String get(String name,
                         String defaultValue)
```
    取得系统属性，如果因为Java安全的限制而失败，则将错误打在Log中，然后返回 defaultValue
    
    Parameters:
    
    name - 属性名
    
    defaultValue - 默认值
    
    Returns:
    
    属性值或defaultValue
    
    See Also:
    
    System.getProperty(String), System.getenv(String)
  - get
```
public static String get(String name,
                         boolean quiet)
```
    取得系统属性，如果因为Java安全的限制而失败，则将错误打在Log中，然后返回 null
    
    Parameters:
    
    name - 属性名
    
    quiet - 安静模式，不将出错信息打在System.err中
    
    Returns:
    
    属性值或null
    
    See Also:
    
    System.getProperty(String), System.getenv(String)
  - get
```
public static String get(String key)
```
    获得System属性
    
    Parameters:
    
    key - 键
    
    Returns:
    
    属性值
    
    See Also:
    
    System.getProperty(String), System.getenv(String)
  - getBoolean
```
public static boolean getBoolean(String key,
                                 boolean defaultValue)
```
    获得boolean类型值
    
    Parameters:
    
    key - 键
    
    defaultValue - 默认值
    
    Returns:
    
    值
  - getInt
```
public static long getInt(String key,
                          int defaultValue)
```
    获得int类型值
    
    Parameters:
    
    key - 键
    
    defaultValue - 默认值
    
    Returns:
    
    值
  - getLong
```
public static long getLong(String key,
                           long defaultValue)
```
    获得long类型值
    
    Parameters:
    
    key - 键
    
    defaultValue - 默认值
    
    Returns:
    
    值
  - props
```
public static Properties props()
```
    Returns:
    
    属性列表
  - getCurrentPID
```
public static long getCurrentPID()
```
    获取当前进程 PID
    
    Returns:
    
    当前进程 ID
  - getClassLoadingMXBean
```
public static ClassLoadingMXBean getClassLoadingMXBean()
```
    返回Java虚拟机类加载系统相关属性
    
    Returns:
    
    ClassLoadingMXBean
    
    Since:
    
    4.1.4
  - getMemoryMXBean
```
public static MemoryMXBean getMemoryMXBean()
```
    返回Java虚拟机内存系统相关属性
    
    Returns:
    
    MemoryMXBean
    
    Since:
    
    4.1.4
  - getThreadMXBean
```
public static ThreadMXBean getThreadMXBean()
```
    返回Java虚拟机线程系统相关属性
    
    Returns:
    
    ThreadMXBean
    
    Since:
    
    4.1.4
  - getRuntimeMXBean
```
public static RuntimeMXBean getRuntimeMXBean()
```
    返回Java虚拟机运行时系统相关属性
    
    Returns:
    
    RuntimeMXBean
    
    Since:
    
    4.1.4
  - getCompilationMXBean
```
public static CompilationMXBean getCompilationMXBean()
```
    返回Java虚拟机编译系统相关属性
    如果没有编译系统，则返回null
    
    Returns:
    
    a CompilationMXBean ，如果没有编译系统，则返回null
    
    Since:
    
    4.1.4
  - getOperatingSystemMXBean
```
public static OperatingSystemMXBean getOperatingSystemMXBean()
```
    返回Java虚拟机运行下的操作系统相关信息属性
    
    Returns:
    
    OperatingSystemMXBean
    
    Since:
    
    4.1.4
  - getMemoryPoolMXBeans
```
public static List<MemoryPoolMXBean> getMemoryPoolMXBeans()
```
    获取Java虚拟机中的MemoryPoolMXBean列表
    The Java virtual machine can have one or more memory pools. It may add or remove memory pools during execution.
    
    Returns:
    
    a list of MemoryPoolMXBean objects.
  - getMemoryManagerMXBeans
```
public static List<MemoryManagerMXBean> getMemoryManagerMXBeans()
```
    获取Java虚拟机中的MemoryManagerMXBean列表
    The Java virtual machine can have one or more memory managers. It may add or remove memory managers during execution.
    
    Returns:
    
    a list of MemoryManagerMXBean objects.
  - getGarbageCollectorMXBeans
```
public static List<GarbageCollectorMXBean> getGarbageCollectorMXBeans()
```
    获取Java虚拟机中的GarbageCollectorMXBean列表
    
    Returns:
    
    GarbageCollectorMXBean列表
  - getJvmSpecInfo
```
public static JvmSpecInfo getJvmSpecInfo()
```
    取得Java Virtual Machine Specification的信息。
    
    Returns:
    
    JvmSpecInfo对象
  - getJvmInfo
```
public static JvmInfo getJvmInfo()
```
    取得Java Virtual Machine Implementation的信息。
    
    Returns:
    
    JvmInfo对象
  - getJavaSpecInfo
```
public static JavaSpecInfo getJavaSpecInfo()
```
    取得Java Specification的信息。
    
    Returns:
    
    JavaSpecInfo对象
  - getJavaInfo
```
public static JavaInfo getJavaInfo()
```
    取得Java Implementation的信息。
    
    Returns:
    
    JavaInfo对象
  - getJavaRuntimeInfo
```
public static JavaRuntimeInfo getJavaRuntimeInfo()
```
    取得当前运行的JRE的信息。
    
    Returns:
    
    JreInfo对象
  - getOsInfo
```
public static OsInfo getOsInfo()
```
    取得OS的信息。
    
    Returns:
    
    OsInfo对象
  - getUserInfo
```
public static UserInfo getUserInfo()
```
    取得User的信息。
    
    Returns:
    
    UserInfo对象
  - getHostInfo
```
public static HostInfo getHostInfo()
```
    取得Host的信息。
    
    Returns:
    
    HostInfo对象
  - getRuntimeInfo
```
public static RuntimeInfo getRuntimeInfo()
```
    取得Runtime的信息。
    
    Returns:
    
    RuntimeInfo对象
  - getTotalMemory
```
public static long getTotalMemory()
```
    获取JVM中内存总大小
    
    Returns:
    
    内存总大小
    
    Since:
    
    4.5.4
  - getFreeMemory
```
public static long getFreeMemory()
```
    获取JVM中内存剩余大小
    
    Returns:
    
    内存剩余大小
    
    Since:
    
    4.5.4
  - getMaxMemory
```
public static long getMaxMemory()
```
    获取JVM可用的内存总大小
    
    Returns:
    
    JVM可用的内存总大小
    
    Since:
    
    4.5.4
  - getTotalThreadCount
```
public static int getTotalThreadCount()
```
    获取总线程数
    
    Returns:
    
    总线程数
  - dumpSystemInfo
```
public static void dumpSystemInfo()
```
    将系统信息输出到System.out中。
  - dumpSystemInfo
```
public static void dumpSystemInfo(PrintWriter out)
```
    将系统信息输出到指定PrintWriter中。
    
    Parameters:
    
    out - PrintWriter输出流
  - append
```
protected static void append(StringBuilder builder,
                             String caption,
                             Object value)
```
    输出到StringBuilder。
    
    Parameters:
    
    builder - StringBuilder对象
    
    caption - 标题
    
    value - 值

Class SystemUtil

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SPECIFICATION_NAME

VERSION

SPECIFICATION_VERSION

VENDOR

SPECIFICATION_VENDOR

VENDOR_URL

HOME

LIBRARY_PATH

TMPDIR

COMPILER

EXT_DIRS

VM_NAME

VM_SPECIFICATION_NAME

VM_VERSION

VM_SPECIFICATION_VERSION

VM_VENDOR

VM_SPECIFICATION_VENDOR

CLASS_VERSION

CLASS_PATH

OS_NAME

OS_ARCH

OS_VERSION

FILE_SEPARATOR

PATH_SEPARATOR

LINE_SEPARATOR

USER_NAME

USER_HOME

USER_DIR

Constructor Detail

SystemUtil

Method Detail

get

get

get

getBoolean

getInt

getLong

props

getCurrentPID

getClassLoadingMXBean

getMemoryMXBean

getThreadMXBean

getRuntimeMXBean

getCompilationMXBean

getOperatingSystemMXBean

getMemoryPoolMXBeans

getMemoryManagerMXBeans

getGarbageCollectorMXBeans

getJvmSpecInfo

getJvmInfo

getJavaSpecInfo

getJavaInfo

getJavaRuntimeInfo

getOsInfo

getUserInfo

getHostInfo

getRuntimeInfo

getTotalMemory

getFreeMemory

getMaxMemory

getTotalThreadCount

dumpSystemInfo

dumpSystemInfo

append