diff --git a/.gitignore b/.gitignore
index 9fbb3c4..f822971 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,13 @@
 *.class
 \.*
 target/
+out/
 
 # Package Files #
 *.jar
 *.war
 *.ear
 
-jieba-analysis.iml
+*.iml
+*.ipr
+*.iws
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..524ca0c
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,27 @@
+apply plugin: 'java'
+apply plugin: 'maven'
+apply plugin: 'idea'
+
+group = 'com.huaban'
+version = '1.0.3-SNAPSHOT'
+
+description = """结巴分词工具(jieba for java)"""
+
+sourceCompatibility = 1.7
+targetCompatibility = 1.7
+tasks.withType(JavaCompile) {
+	options.encoding = 'UTF-8'
+}
+
+configurations.all {
+}
+
+repositories {
+     maven {url "http://maven.aliyun.com/nexus/content/groups/public"}   
+     maven { url "https://oss.sonatype.org/content/repositories/snapshots" }
+     maven { url "http://repo.maven.apache.org/maven2" }
+}
+dependencies {
+    compile group: 'org.apache.commons', name: 'commons-lang3', version:'3.3.1'
+    testCompile group: 'junit', name: 'junit', version:'4.8'
+}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..c545d94
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Sat Jul 29 16:48:54 CST 2017
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.2-bin.zip
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..4ef3a87
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,171 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+for s in "${@}" ; do
+    s=\"$s\"
+    APP_ARGS=$APP_ARGS" "$s
+done
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- "$DEFAULT_JVM_OPTS" "$JAVA_OPTS" "$GRADLE_OPTS" "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..dcbd3dc
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'jieba-analysis'
diff --git a/src/main/java/com/huaban/analysis/jieba/WordDictionary.java b/src/main/java/com/huaban/analysis/jieba/WordDictionary.java
index 8cb1e53..b0aed58 100644
--- a/src/main/java/com/huaban/analysis/jieba/WordDictionary.java
+++ b/src/main/java/com/huaban/analysis/jieba/WordDictionary.java
@@ -9,28 +9,38 @@
 import java.io.InputStreamReader;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Locale;
-import java.util.Map;
+import java.util.*;
 import java.util.Map.Entry;
-import java.util.Set;
 
 
 public class WordDictionary {
-    private static WordDictionary singleton;
+    private static volatile WordDictionary singleton;
     private static final String MAIN_DICT = "/dict.txt";
     private static String USER_DICT_SUFFIX = ".dict";
 
-    public final Map<String, Double> freqs = new HashMap<String, Double>();
+    public final Map<String, ComputedFreq> freqs = new HashMap<String, ComputedFreq>();
     public final Set<String> loadedPath = new HashSet<String>();
     private Double minFreq = Double.MAX_VALUE;
     private Double total = 0.0;
     private DictSegment _dict;
+    private boolean useDefaultDict = true;
 
+    private static final String CONFIG_NAME = "jieba.defaultDict";
 
     private WordDictionary() {
-        this.loadDict();
+        loadConfig();
+
+        if (this.useDefaultDict) {
+            this.loadDict();
+        }
+    }
+
+    private void loadConfig() {
+        String configString = System.getenv(CONFIG_NAME);
+        if (configString == null) {
+            configString = System.getProperty(CONFIG_NAME, "true");
+        }
+        this.useDefaultDict = Boolean.valueOf(configString);
     }
 
 
@@ -100,16 +110,12 @@ public void loadDict() {
                     continue;
 
                 String word = tokens[0];
-                double freq = Double.valueOf(tokens[1]);
+                int freq = Integer.valueOf(tokens[1]);
                 total += freq;
                 word = addWord(word);
-                freqs.put(word, freq);
-            }
-            // normalize
-            for (Entry<String, Double> entry : freqs.entrySet()) {
-                entry.setValue((Math.log(entry.getValue() / total)));
-                minFreq = Math.min(entry.getValue(), minFreq);
+                freqs.put(word, new ComputedFreq(freq));
             }
+            normalizeFreqs();
             System.out.println(String.format(Locale.getDefault(), "main dict load finished, time elapsed %d ms",
                 System.currentTimeMillis() - s));
         }
@@ -127,6 +133,14 @@ public void loadDict() {
         }
     }
 
+    private void normalizeFreqs() {
+        // normalize
+        for (Entry<String, ComputedFreq> entry : freqs.entrySet()) {
+            entry.getValue().compFreq = Math.log((double) entry.getValue().freq / total);
+            minFreq = Math.min(entry.getValue().compFreq, minFreq);
+        }
+    }
+
 
     private String addWord(String word) {
         if (null != word && !"".equals(word.trim())) {
@@ -144,9 +158,10 @@ public void loadUserDict(Path userDict) {
     }
 
 
-    public void loadUserDict(Path userDict, Charset charset) {                
+    public void loadUserDict(Path userDict, Charset charset) {
+        BufferedReader br = null;
         try {
-            BufferedReader br = Files.newBufferedReader(userDict, charset);
+            br = Files.newBufferedReader(userDict, charset);
             long s = System.currentTimeMillis();
             int count = 0;
             while (br.ready()) {
@@ -160,18 +175,33 @@ public void loadUserDict(Path userDict, Charset charset) {
 
                 String word = tokens[0];
 
-                double freq = 3.0d;
-                if (tokens.length == 2)
-                    freq = Double.valueOf(tokens[1]);
-                word = addWord(word); 
-                freqs.put(word, Math.log(freq / total));
+                int freq = 3;
+                if (tokens.length >= 2)
+                    freq = Integer.valueOf(tokens[1]);
+                word = addWord(word);
+                ComputedFreq computedFreq = freqs.get(word);
+                if (computedFreq == null) {
+                    freqs.put(word, new ComputedFreq(freq));
+                } else {
+                    computedFreq.freq += freq;
+                }
+                total += freq;
                 count++;
             }
+            normalizeFreqs();
             System.out.println(String.format(Locale.getDefault(), "user dict %s load finished, tot words:%d, time elapsed:%dms", userDict.toString(), count, System.currentTimeMillis() - s));
-            br.close();
         }
         catch (IOException e) {
             System.err.println(String.format(Locale.getDefault(), "%s: load user dict failure!", userDict.toString()));
+        } finally {
+            if (br != null) {
+                try {
+                    br.close();
+                } catch (IOException e) {
+                    System.err.println(String.format(Locale.getDefault(),
+                            "%s: load user dict failure! %s", userDict.toString(), e.getMessage()));
+                }
+            }
         }
     }
 
@@ -185,11 +215,23 @@ public boolean containsWord(String word) {
         return freqs.containsKey(word);
     }
 
+    public boolean isUseDefaultDict() {
+        return useDefaultDict;
+    }
 
     public Double getFreq(String key) {
         if (containsWord(key))
-            return freqs.get(key);
+            return freqs.get(key).compFreq;
         else
             return minFreq;
     }
+
+    private static class ComputedFreq {
+        private double compFreq;
+        private int freq;
+
+        public ComputedFreq(int freq) {
+            this.freq = freq;
+        }
+    }
 }
diff --git a/src/test/java/com/huaban/analysis/jieba/WordDictionaryTest.java b/src/test/java/com/huaban/analysis/jieba/WordDictionaryTest.java
new file mode 100644
index 0000000..762895c
--- /dev/null
+++ b/src/test/java/com/huaban/analysis/jieba/WordDictionaryTest.java
@@ -0,0 +1,59 @@
+/**
+ * (C) Copyright 2017 alex qian
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+package com.huaban.analysis.jieba;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Paths;
+
+/**
+ *
+ * WordDictionaryTest
+ *
+ * @author alex.Q
+ * @date 2017/7/29
+ */
+public class WordDictionaryTest {
+
+    @Test
+    public void test_loadDict() throws URISyntaxException {
+        WordDictionary wordDict = WordDictionary.getInstance();
+        double d = wordDict.getFreq("司机");
+        System.out.println(d);
+        URL url = ClassLoader.getSystemResource("test_user.dict");
+        wordDict.loadUserDict(Paths.get(url.toURI()));
+        d = wordDict.getFreq("司机");
+        System.out.println(d);
+    }
+
+    @Test
+    public void test_useDefaultDict() {
+        WordDictionary wordDict = WordDictionary.getInstance();
+        Assert.assertTrue(wordDict.isUseDefaultDict());
+    }
+
+    @Test
+    public void test_useDefaultDict2() {
+        System.setProperty("jieba.defaultDict", "false");
+        WordDictionary wordDict = WordDictionary.getInstance();
+        Assert.assertTrue(wordDict.isUseDefaultDict() == false);
+    }
+
+}
diff --git a/src/test/resources/test_user.dict b/src/test/resources/test_user.dict
new file mode 100644
index 0000000..4e9743d
--- /dev/null
+++ b/src/test/resources/test_user.dict
@@ -0,0 +1,2 @@
+老司机 10 n
+司机 1000 n
\ No newline at end of file