基于spring-web(4.1.4)包的org.springframework.web.bind.ServletRequestUtils工具类对HttpServletRequest获取的传递入参获取request.getParameter进行常见默认数据类型（整型IntParser、长整型LongParser、浮点数类型FloatParser、双精度浮点数、布尔型类型DoubleParser、字符串类型StringParser）的转换，源码如下所示
package org.springframework.web.bind;
import javax.servlet.ServletRequest;
public abstract class ServletRequestUtils
{
private static final IntParser INT_PARSER = new IntParser(null);
private static final LongParser LONG_PARSER = new LongParser(null);
private static final FloatParser FLOAT_PARSER = new FloatParser(null);
private static final DoubleParser DOUBLE_PARSER = new DoubleParser(null);
private static final BooleanParser BOOLEAN_PARSER = new BooleanParser(null);
private static final StringParser STRING_PARSER = new StringParser(null);
public static Integer getIntParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return Integer.valueOf(getRequiredIntParameter(request, name));
}
public static int getIntParameter(ServletRequest request, String name, int defaultVal)
{
if (request.getParameter(name) == null)
return defaultVal;
try
{
return getRequiredIntParameter(request, name);
} catch (ServletRequestBindingException ex) {
}
return defaultVal;
}
public static int[] getIntParameters(ServletRequest request, String name)
{
try
{
return getRequiredIntParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new int[0];
}
public static int getRequiredIntParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return INT_PARSER.parseInt(name, request.getParameter(name));
}
public static int[] getRequiredIntParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return INT_PARSER.parseInts(name, request.getParameterValues(name));
}
public static Long getLongParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return Long.valueOf(getRequiredLongParameter(request, name));
}
public static long getLongParameter(ServletRequest request, String name, long defaultVal)
{
if (request.getParameter(name) == null)
return defaultVal;
try
{
return getRequiredLongParameter(request, name);
} catch (ServletRequestBindingException ex) {
}
return defaultVal;
}
public static long[] getLongParameters(ServletRequest request, String name)
{
try
{
return getRequiredLongParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new long[0];
}
public static long getRequiredLongParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return LONG_PARSER.parseLong(name, request.getParameter(name));
}
public static long[] getRequiredLongParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return LONG_PARSER.parseLongs(name, request.getParameterValues(name));
}
public static Float getFloatParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return Float.valueOf(getRequiredFloatParameter(request, name));
}
public static float getFloatParameter(ServletRequest request, String name, float defaultVal)
{
if (request.getParameter(name) == null)
return defaultVal;
try
{
return getRequiredFloatParameter(request, name);
} catch (ServletRequestBindingException ex) {
}
return defaultVal;
}
public static float[] getFloatParameters(ServletRequest request, String name)
{
try
{
return getRequiredFloatParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new float[0];
}
public static float getRequiredFloatParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return FLOAT_PARSER.parseFloat(name, request.getParameter(name));
}
public static float[] getRequiredFloatParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return FLOAT_PARSER.parseFloats(name, request.getParameterValues(name));
}
public static Double getDoubleParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return Double.valueOf(getRequiredDoubleParameter(request, name));
}
public static double getDoubleParameter(ServletRequest request, String name, double defaultVal)
{
if (request.getParameter(name) == null)
return defaultVal;
try
{
return getRequiredDoubleParameter(request, name);
} catch (ServletRequestBindingException ex) {
}
return defaultVal;
}
public static double[] getDoubleParameters(ServletRequest request, String name)
{
try
{
return getRequiredDoubleParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new double[0];
}
public static double getRequiredDoubleParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return DOUBLE_PARSER.parseDouble(name, request.getParameter(name));
}
public static double[] getRequiredDoubleParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return DOUBLE_PARSER.parseDoubles(name, request.getParameterValues(name));
}
public static Boolean getBooleanParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return Boolean.valueOf(getRequiredBooleanParameter(request, name));
}
public static boolean getBooleanParameter(ServletRequest request, String name, boolean defaultVal)
{
if (request.getParameter(name) == null)
return defaultVal;
try
{
return getRequiredBooleanParameter(request, name);
} catch (ServletRequestBindingException ex) {
}
return defaultVal;
}
public static boolean[] getBooleanParameters(ServletRequest request, String name)
{
try
{
return getRequiredBooleanParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new boolean[0];
}
public static boolean getRequiredBooleanParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return BOOLEAN_PARSER.parseBoolean(name, request.getParameter(name));
}
public static boolean[] getRequiredBooleanParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return BOOLEAN_PARSER.parseBooleans(name, request.getParameterValues(name));
}
public static String getStringParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
if (request.getParameter(name) == null)
return null;
return getRequiredStringParameter(request, name);
}
public static String getStringParameter(ServletRequest request, String name, String defaultVal)
{
String val = request.getParameter(name);
return ((val != null) ? val : defaultVal);
}
public static String[] getStringParameters(ServletRequest request, String name)
{
try
{
return getRequiredStringParameters(request, name);
} catch (ServletRequestBindingException ex) {
}
return new String[0];
}
public static String getRequiredStringParameter(ServletRequest request, String name)
throws ServletRequestBindingException
{
return STRING_PARSER.validateRequiredString(name, request.getParameter(name));
}
public static String[] getRequiredStringParameters(ServletRequest request, String name)
throws ServletRequestBindingException
{
return STRING_PARSER.validateRequiredStrings(name, request.getParameterValues(name));
}
private static class StringParser extends ServletRequestUtils.ParameterParser<String>
{
private StringParser()
{
super(null);
}
protected String getType() {
return "string";
}
protected String doParse(String parameter) throws NumberFormatException
{
return parameter;
}
public String validateRequiredString(String name, String value) throws ServletRequestBindingException {
validateRequiredParameter(name, value);
return value;
}
public String[] validateRequiredStrings(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
String[] arrayOfString = values; int i = arrayOfString.length; for (int j = 0; j < i; ++j) { String value = arrayOfString[j];
validateRequiredParameter(name, value);
}
return values;
}
}
private static class BooleanParser extends ServletRequestUtils.ParameterParser<Boolean>
{
private BooleanParser()
{
super(null);
}
protected String getType() {
return "boolean";
}
protected Boolean doParse(String parameter) throws NumberFormatException
{
return Boolean.valueOf((parameter.equalsIgnoreCase("true")) || (parameter.equalsIgnoreCase("on")) ||
(parameter
.equalsIgnoreCase("yes")) ||
(parameter.equals("1")));
}
public boolean parseBoolean(String name, String parameter) throws ServletRequestBindingException {
return ((Boolean)parse(name, parameter)).booleanValue();
}
public boolean[] parseBooleans(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
boolean[] parameters = new boolean[values.length];
for (int i = 0; i < values.length; ++i)
parameters[i] = parseBoolean(name, values[i]);
return parameters;
}
}
private static class DoubleParser extends ServletRequestUtils.ParameterParser<Double>
{
private DoubleParser()
{
super(null);
}
protected String getType() {
return "double";
}
protected Double doParse(String parameter) throws NumberFormatException
{
return Double.valueOf(parameter);
}
public double parseDouble(String name, String parameter) throws ServletRequestBindingException {
return ((Double)parse(name, parameter)).doubleValue();
}
public double[] parseDoubles(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
double[] parameters = new double[values.length];
for (int i = 0; i < values.length; ++i)
parameters[i] = parseDouble(name, values[i]);
return parameters;
}
}
private static class FloatParser extends ServletRequestUtils.ParameterParser<Float>
{
private FloatParser()
{
super(null);
}
protected String getType() {
return "float";
}
protected Float doParse(String parameter) throws NumberFormatException
{
return Float.valueOf(parameter);
}
public float parseFloat(String name, String parameter) throws ServletRequestBindingException {
return ((Float)parse(name, parameter)).floatValue();
}
public float[] parseFloats(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
float[] parameters = new float[values.length];
for (int i = 0; i < values.length; ++i)
parameters[i] = parseFloat(name, values[i]);
return parameters;
}
}
private static class LongParser extends ServletRequestUtils.ParameterParser<Long>
{
private LongParser()
{
super(null);
}
protected String getType() {
return "long";
}
protected Long doParse(String parameter) throws NumberFormatException
{
return Long.valueOf(parameter);
}
public long parseLong(String name, String parameter) throws ServletRequestBindingException {
return ((Long)parse(name, parameter)).longValue();
}
public long[] parseLongs(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
long[] parameters = new long[values.length];
for (int i = 0; i < values.length; ++i)
parameters[i] = parseLong(name, values[i]);
return parameters;
}
}
private static class IntParser extends ServletRequestUtils.ParameterParser<Integer>
{
private IntParser()
{
super(null);
}
protected String getType() {
return "int";
}
protected Integer doParse(String s) throws NumberFormatException
{
return Integer.valueOf(s);
}
public int parseInt(String name, String parameter) throws ServletRequestBindingException {
return ((Integer)parse(name, parameter)).intValue();
}
public int[] parseInts(String name, String[] values) throws ServletRequestBindingException {
validateRequiredParameter(name, values);
int[] parameters = new int[values.length];
for (int i = 0; i < values.length; ++i)
parameters[i] = parseInt(name, values[i]);
return parameters;
}
}
private static abstract class ParameterParser<T>
{
protected final T parse(String name, String parameter)
throws ServletRequestBindingException
{
validateRequiredParameter(name, parameter);
try {
return doParse(parameter);
}
catch (NumberFormatException ex)
{
throw new ServletRequestBindingException("Required " +
getType() + " parameter '" + name + "' with value of '" + parameter + "' is not a valid number", ex);
}
}
protected final void validateRequiredParameter(String name, Object parameter)
throws ServletRequestBindingException
{
if (parameter == null)
throw new MissingServletRequestParameterException(name, getType());
}
protected abstract String getType();
protected abstract T doParse(String paramString)
throws NumberFormatException;
}
}