java operation properties configuration file

There is a class Properties (Java.util.Properties) in Java, which is mainly used to read Java configuration files and store some values ​​that may need to be changed in properties for configuration, usually as .properties files. , in fact, it is an ordinary text file. The format of the file content is the "key=value" format, and the text annotation information can be annotated with "#". Try to use UTF-8 format for storage. The classes provided by jdk itself have shortcomings, so we usually use the commons-configuration framework for analysis.

1.1.1. Properties class diagram

##1.1.2. Read

Properties configurationfileCommonly used methods

1. Use the getResourceAsStream(String name) method of the java.lang.Class class
InputStream in = getClass().getResourceAsStream("File name");

2. Use stream operation

InputStream in = new BufferedInputStream(new FileInputStream(filepath));

1.1.3. Disadvantages

1. The format must be k=v without spaces.

2. Changed values ​​cannot be refreshed regularly(For example, the online environment modification value program still reads the old value ). You need to write your own program control.

#3. The values ​​are all of the string type and need to be converted according to needs when obtained by yourself.

Based on the above shortcomings, we can use the org.apache.commons.configuration class to solve the problem. The following is read in daily development propertiesEncapsulation.

1.1.4. Use of commons-configuration framework

1.1.4.1. maven

Package import

 <dependency>
        <groupId>commons-configuration</groupId>
        <artifactId>commons-configuration</artifactId>
        <version>1.8</version>
</dependency>

1.1.4.2. Tool class encapsulation

package cn.xhgg.common.configuration;
 
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
 
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
/**
 * 这个类型的配置,文件首先需要有配置文件,其次配置文件应该写入该类,再则配置文件的编码方式必须是UTF8
 */
public class PropertiesConfigUtil {
private static Logger log = LoggerFactory.getLogger(PropertiesConfigUtil.class);
 
public static final String PROPS_SUFFIX = ".properties";
private static Map<String, PropertiesConfiguration> configMap = new ConcurrentHashMap<String, PropertiesConfiguration>();
private static PropertiesConfiguration getConfig(String configName) {
//去除空格
configName = configName.trim();
//有后缀使用后缀 没后缀 添加后缀
String configSig = StringUtils.endsWith(configName, PROPS_SUFFIX) ? configName : configName+PROPS_SUFFIX;
if (configMap.containsKey(configSig)) {
return configMap.get(configSig);
}
PropertiesConfiguration config = null;
try {
config=new PropertiesConfiguration();
config.setEncoding("UTF-8");
config.load(configSig);
//默认五秒检查一次
config.setReloadingStrategy(new FileChangedReloadingStrategy());
config.setThrowExceptionOnMissing(true);
configMap.put(configSig, config);
} catch (ConfigurationException e) {
e.printStackTrace();
}
return config;
}
public static Map<String, String> getKeyValuePairs(String configSig) {
PropertiesConfiguration config = getConfig(configSig);
if (config == null) {
return null;
}
Iterator<String> iters = config.getKeys();
Map<String, String> retMap = new HashMap<String, String>();
while (iters.hasNext()) {
String beforeKey = iters.next();
if (retMap.containsKey(beforeKey)) {
log.warn(configSig + " configKey:" + beforeKey + " repeated!!");
}
retMap.put(beforeKey, config.getString(beforeKey));
}
return retMap;
}
/**
 * 通过PropertiesConfiguration取得参数的方法
 * <p>
 * 
 * @return 。
 */
static public String getString(String configSig, String key) {
return getConfig(configSig).getString(key);
}
 
static public String getString(String configSig, String key, String defaultValue) {
return getConfig(configSig).getString(key, defaultValue);
}
 
static public int getInt(String configSig, String key) {
return getConfig(configSig).getInt(key);
}
 
static public int getInt(String configSig, String key, int defaultValue) {
return getConfig(configSig).getInt(key, defaultValue);
}
 
static public boolean getBoolean(String configSig, String key) {
return getConfig(configSig).getBoolean(key);
}
 
static public boolean getBoolean(String configSig, String key, boolean defaultValue) {
return getConfig(configSig).getBoolean(key, defaultValue);
}
 
static public double getDouble(String configSig, String key) {
return getConfig(configSig).getDouble(key);
}
 
static public double getDouble(String configSig, String key, double defaultValue) {
return getConfig(configSig).getDouble(key, defaultValue);
}
 
static public float getFloat(String configSig, String key) {
return getConfig(configSig).getFloat(key);
}
 
static public float getFloat(String configSig, String key, float defaultValue) {
return getConfig(configSig).getFloat(key, defaultValue);
}
 
static public long getLong(String configSig, String key) {
return getConfig(configSig).getLong(key);
}
 
static public long getLong(String configSig, String key, long defaultValue) {
return getConfig(configSig).getLong(key, defaultValue);
}
 
static public short getShort(String configSig, String key) {
return getConfig(configSig).getShort(key);
}
 
static public short getShort(String configSig, String key, short defaultValue) {
return getConfig(configSig).getShort(key, defaultValue);
}
 
static public List<Object> getList(String configSig, String key) {
return getConfig(configSig).getList(key);
}
 
static public List<Object> getList(String configSig, String key, List<Object> defaultValue) {
return getConfig(configSig).getList(key, defaultValue);
}
 
static public byte getByte(String configSig, String key) {
return getConfig(configSig).getByte(key);
}
 
static public byte getByte(String configSig, String key, byte defaultValue) {
return getConfig(configSig).getByte(key, defaultValue);
}
 
static public String[] getStringArray(String configSig, String key) {
return getConfig(configSig).getStringArray(key);
}
}

1.1.4.3. Introduce the

properties test file

rabbitmq.properties

and configure it as follows:

#rpc 模式rmq
rpc.rabbit.host=l-opsdev3.ops.bj0.jd.com
rpc.rabbit.port=5672
rpc.rabbit.username=jd_vrmphoto
rpc.rabbit.password=jd_vrmphoto
rpc.rabbit.vhost=jd/vrmphoto
rpc.rabbit.queue=rpc_queue
rpc.rabbit.exchange=photoworker
rpc.rabbit.key=photoworker.rpc

##1.1.4.4. Test

PropertiesConfigUtil config=new PropertiesConfigUtil();
String username = config.getString("rabbitmq", "rpc.rabbit.username");
System.out.println(username);

Output result:

jd_vrmphoto

ok,

Done.

1.1.4.5. Notes

1. The encoding is best

UTF-8

unified. ReloadingStrategy strategy selection. You can look at the specific implementation classes and usage scenarios. I generally use the FileChangedReloadingStrategy class.

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