http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); X|{Tljn
} )]C]KB
for(int i=0;i<nEndPos.length-1;i++) aO<7a 6
{ hc q&`Gun
nEndPos = nStartPos[i+1]; 8C*@d_=q
} WBWW7HK
nEndPos[nEndPos.length-1] = nFileLength; ]?=87w
} " 7^nRJy
} p\=T#lb
*xNc^&.
wx3_?8z/O
//启动子线程 1}\p:`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Sfd|0^
for(int i=0;i<nStartPos.length;i++) k^%=\c
{ 8<Iq)A]'Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), % vUU Fub
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I9qZE=i
nStartPos,nEndPos,i); gP QOv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $}WT"K
fileSplitterFetch.start(); sr;&/l#7h
} >ZOlSLu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5m~9Vl-&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gaz7u8$A=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }2;P`s
nEndPos = " + nFileLength); b69nj
// fileSplitterFetch[nPos.length-1].start(); N0w?c 5>
O+o)z6(
nvrh7l9nX
//等待子线程结束 ^.LB(GZ,
//int count = 0; j<(E%KN3
//是否结束while循环 fU|v[
boolean breakWhile = false; .S|7$_9;b
sn:VMHrOT
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while(!bStop) 6m?<"y8]
{ ,VVA^'+
write_nPos(); hb;CpA
Utility.sleep(500); D?_K5a&v,
breakWhile = true; "G@K(bnHn
l0,VN,$Yl
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for(int i=0;i<nStartPos.length;i++) B%\&Q@X
{ _\\Al v.
if(!fileSplitterFetch.bDownOver) ]\^O(BzB
{ Nt$4;
breakWhile = false; ]YI9
break; u1X^#K$nu'
} 9o>D Uc
} CPy>sV3Ru0
if(breakWhile) Z4/D38_
break; &/UfXKr
+45SKu=
c~(61Sn]
//count++; q{&c?l*2
//if(count>4) D-{*3?x
// siteStop(); lW|=rq-|
} )$S=iL8(
C1NU6iV^z
Xsa8YP9
System.err.println("文件下载结束！"); PyfWIU7O
} =OFhM7
catch(Exception e){e.printStackTrace ();} Q$5t~*$`
} 4\-11!'08
=?C <@
k( 0;>)<i
//获得文件长度 nRBS&&V
public long getFileSize() :^kAFLU
{ )$TN%hV!
int nFileLength = -1; \Vx^u}3O
try{ FQO=}0Hl
URL url = new URL(siteInfoBean.getSSiteURL()); nlB'@r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v Z]j%c@
httpConnection.setRequestProperty("User-Agent","NetFox"); 4o}{3! m
n}a`|Nbk
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int responseCode=httpConnection.getResponseCode(); =%~- M
if(responseCode>=400) ftRFG
{ dGk"`/@
processErrorCode(responseCode); }T$BU>z33N
return -2; //-2 represent access is error K/*R}X
} Q*<KX2O
7<WUjK|
A2gFY}
String sHeader; ;l!<A
3H!]X M
i_N8)Z;r
for(int i=1;;i++) CsZm8oL$
{ Mbxl{M >
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fCUx93,>z
//Utility.log(in.readLine()); 15jQ87)
sHeader=httpConnection.getHeaderFieldKey(i); )dfhy
if(sHeader!=null) t[2b~peNI
{ }Ecv6&G
if(sHeader.equals("Content-Length")) K*5gb^Ul
{ f@;pN=PS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g "Du]_,
break; uEb:uENk'(
} VLm\PS
} yJ!26
else ~4+Y BN
break; 'sIne>
} O W.CU=XU
} w98M#GqV
catch(IOException e){e.printStackTrace ();} VX8rM!3
catch(Exception e){e.printStackTrace ();} 1_{e*=/y
H4`>B>\
.pPuBJL]<
Utility.log(nFileLength); b|AjB:G
wzy[sB274
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return nFileLength; @}6<,;|DQ
} 1P"7.{
W)ug%@)
2 )o2d^^
//保存下载信息（文件指针位置） Ut2T:%m{
private void write_nPos() qZ!kVrmg&
{ ykbfK$jz
try{ T&[6
output = new DataOutputStream(new FileOutputStream(tmpFile)); bxYSZCo*
output.writeInt(nStartPos.length); mQ1
for(int i=0;i<nStartPos.length;i++) U<&=pv
{ ]a/dvj}
// output.writeLong(nPos); 5xr>B7MRM?
output.writeLong(fileSplitterFetch.nStartPos); hkl0N%[
output.writeLong(fileSplitterFetch.nEndPos); &Y1h=,KR9
} f4pIF"U9>
output.close(); ZgEV-.>P
} =LLpJ+
catch(IOException e){e.printStackTrace ();} 5rLx b
catch(Exception e){e.printStackTrace ();} fUf1G{4
} 69$R.
ZhCd**
1/mBp+D
//读取保存的下载信息（文件指针位置） Sydl[c pH$
private void read_nPos() W3[>IH"+
{ {f/]K GGk
try{ %1p-DX6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <m\Y$Wv
int nCount = input.readInt(); xkFa
nStartPos = new long[nCount]; 3(K.:376
nEndPos = new long[nCount]; 8!35 K
for(int i=0;i<nStartPos.length;i++) Vp; `!+z"
{ rF[-4t %
nStartPos = input.readLong(); c*\i%I#f2
nEndPos = input.readLong(); sHPAr}14
} >x%HqP#_V
input.close(); >y8>OJ?A7-
} )6%*=-
catch(IOException e){e.printStackTrace ();} }=f\WWJf0
catch(Exception e){e.printStackTrace ();} L44|/~
} ~6t<`&f
#Ev}Gf+5Q
fr`#s\JKw
private void processErrorCode(int nErrorCode) [@/p 8I
{ 0.+Eo.AX4M
System.err.println("Error Code : " + nErrorCode); i?d545. u
} 0;LF>+fJ
XSof{:V
xKBi".wA
//停止文件下载 U*{0,Ue'
public void siteStop() W2-l_{
{ A?04,l]y
bStop = true; G)YmaHeI;[
for(int i=0;i<nStartPos.length;i++) - s'W^(
fileSplitterFetch.splitterStop(); Q'jGNWep
eXsp0!v
~rI2 RJ
} *MfH\X379
} mEYfsO
//负责部分文件的抓取 9[\do@
**FileSplitterFetch.java :I"22EH
*/ TT9 \m=7
package NetFox; k;<@2C
,Vj&
:55a9d1bL
import java.io.*; RLex#j
import java.net.*; 13 L&f\b
2V;{@k
z2Wblh"_
public class FileSplitterFetch extends Thread { +fM8
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String sURL; //File URL 2sgp$r
long nStartPos; //File Snippet Start Position VDv.N@)7
long nEndPos; //File Snippet End Position zk3\v "
int nThreadID; //Thread's ID 28M^F~0
boolean bDownOver = false; //Downing is over 45wqX h
boolean bStop = false; //Stop identical _~tF2`,Y_p
FileAccessI fileAccessI = null; //File Access interface Ha]vG@?+
416}# Mk
#k/T\PQ0s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }LS.bQKqi,
{ +68age;dM
this.sURL = sURL; 6qmV/DL
this.nStartPos = nStart; nF]E":
this.nEndPos = nEnd; %OHWGac"i
nThreadID = id; Tt{X(I} J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GMZ6 dK
} s^6,"C
2N |iOog
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public void run() V/DMkO#a
{ };}N1[D
while(nStartPos < nEndPos && !bStop) dm_Pz\*
{ qp*~|
%L)QTv/
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try{ )mAD<y+
URL url = new URL(sURL); JgHYuLB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6)=;cc{Vr
httpConnection.setRequestProperty("User-Agent","NetFox"); 6NyUGGRq
String sProperty = "bytes="+nStartPos+"-"; O%bltNEx1
httpConnection.setRequestProperty("RANGE",sProperty); NMg(tmh
Utility.log(sProperty); ~mvv :u
n(LO`{
[vuikJP>1k
InputStream input = httpConnection.getInputStream(); _qOynW
//logResponseHead(httpConnection); H/ ejO_{
=Gj~:|;$
OcpvY~"Pr
byte[] b = new byte[1024]; 4_2oDcdf
int nRead; {C?$osrr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m@I}$
{ je#LD
nStartPos += fileAccessI.write(b,0,nRead); Omn$O>
//if(nThreadID == 1) hxJKYU^%m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +3AX1o%p,#
} QTF1~A\
HnFH|H<Uf
QA~F
Utility.log("Thread " + nThreadID + " is over!"); L{;Q6_m
bDownOver = true; Z s|*+[
//nPos = fileAccessI.write (b,0,nRead); (I;81h`1G
} kuLur)^
catch(Exception e){e.printStackTrace ();} h)W#
} IcqzMmb
} zA|lbJz=GY
=d~pr:.F
3 %r*~#nz
//打印回应的头信息 A? jaS9 &)
public void logResponseHead(HttpURLConnection con) :.BjJ2[S
{ ; %AgKgV
for(int i=1;;i++) Rq",;,0ZJ
{ MVQ6I/EA4
String header=con.getHeaderFieldKey(i); =D?HL?
if(header!=null) zmuRn4Nv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MYxuQ|w
Utility.log(header+" : "+con.getHeaderField(header)); DuAix)#FN9
else pnuwjU-
break; N5#j}tT
} ,G?Kb#
} P A*U\
Q>\DM'{:4
,0nrSJED
public void splitterStop() d7&d FvG
{ Ps0<CUyI
bStop = true; eLHhfu;k
} x}`)'a[
m,6u+Z,
E)p[^1WC
} ^xgPL'
BlT)hG(M>
H8@z/
/* *U\`HUW
**FileAccess.java 7FaF]G
*//文件访问(定位，写) })PU`?f
package NetFox; C!v%6[
import java.io.*; BGH'&t_5
KG(l=? N
#IqRu:csp
public class FileAccessI implements Serializable{ V!@6Nv
FSkX95
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6"[,
RandomAccessFile oSavedFile; ?caHS2%?ae
long nPos; _x$Eq: i
6I_4{
Y2ON!Rno
public FileAccessI() throws IOException v$;URF%^
{ a7b1c!
this("",0); U: <
} J*%IvRg
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&`]T#">
public FileAccessI(String sName,long nPos) throws IOException RA+M.
{ X}QcXc.d
oSavedFile = new RandomAccessFile(sName,"rw"); [oXr6M:
this.nPos = nPos; @L607[!?
oSavedFile.seek(nPos); 8{&.[SC7
} %l%2 hvGZ
?d3<GhzlR3
w&hCtc
public synchronized int write(byte[] b,int nStart,int nLen) [%Z{Mp'g
{ @o<B>$tbu4
int n = -1; VGCd)&s
try{ &[PA?#I`
oSavedFile.write(b,nStart,nLen); E3CwA8)k
n = nLen; KNF{NFk
} )C0Iy.N-
catch(IOException e) *xx)j:Sc2
{ r0\C2g_X
e.printStackTrace (); {8;}y[R
} B1Z;
-" r4
]h`d>#Hw!
return n; 1p-<F3;
} qckRX+P`
(II#9n)
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} (enOj0
%bG\
']^]z".H
/* \mt Y_O
**SiteInfoBean.java `Xi)';p
*/ bXM&VW?OP
package NetFox; \4fuC6d2
%_39Wa
['6Sq@c)
public class SiteInfoBean { NUuIhB+
YQ1rS X3
%r(qQM.Pl
private String sSiteURL; //Site's URL SapVS*yx@
private String sFilePath; //Saved File's Path Cs vwc%
private String sFileName; //Saved File's Name X7?14W
private int nSplitter; //Count of Splited Downloading File -2C^M> HZ
f$?`50D"1
pG v*{.
public SiteInfoBean() |$GPJaNqa
{//nSplitter的缺省值为5 Hr}\-$
//default value of nSplitter is 5 GJF ,w{J
this("","","",5); S[l z>I
} 2c*}1 _
Q} -YD.bx3
Uw)B(;Hy?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) T#Z#YMk
{ O_DT7;g
sSiteURL= sURL; m_;XhO
sFilePath = sPath; 16~5;u
sFileName = sName; W6u(+P]("
this.nSplitter = nSpiltter; ?. L]QU
TyR@3H
&TN.6Hm3
} 4dI`
b>} )G7b}
i\K88B&24
public String getSSiteURL() ,nUovWN07
{ Q[T)jo,j%
return sSiteURL; Yic4|N?u
} Gy'/)}}Z
|B2>}Y/
BG1hk!
public void setSSiteURL(String value) MTbCL53!-
{ y8v0>V0)
sSiteURL = value; a\p`J9Z@
} vhU#<59a1
BGstf4v>A<
gU@R
public String getSFilePath() Iqj?wI1)
{ @k-GyV-v
return sFilePath; <yw=+hz[u
} ,GtN6?
JUq7R%"h6
+N|t:8qaf
public void setSFilePath(String value) ndvt $*
{ AFsYP/g]
sFilePath = value; MJn=
} NMN&mJsmh
^>y|{;`
\rH0=~F-P
public String getSFileName() 0p*Oxsy
{ w)>/fG|;
return sFileName; :{-/b
} FlbM(ofY
e"Tr0k
3_J({
public void setSFileName(String value) }AS3]Lub@
{ 8(!?y[
sFileName = value; h~Z:YY)4
} ^jk-GRD*
rFW,x_*_vP
kr44@!s+'
public int getNSplitter() FJsM3|{2=d
{ UQBc$`v
return nSplitter; T4;gF6(0]
} ]C-a[
]1q`N7
#V@vz#bo=
public void setNSplitter(int nCount) fDChq[LAn
{ T>5N$i
nSplitter = nCount; Ye/Y<Ij
} %(r.`I$
} h9&0"LHr
A%EGu4
}#Kl6x
/* w!Ii
**Utility.java `pd+as
*/ J c:j7}OOV
package NetFox; jZ<f-Ff0
.6iJ:A6T
P#,g5
public class Utility { 80LN(0?x
2KNs,4X@
Et;Ubj"+
public Utility() j__l'?s
{ [-nPHmZV[
G;J!3A;TE
h-%RSei5
} X$SXDb~G
[qxDCuxq
//线程睡眠 6D4 j];~X
public static void sleep(int nSecond) 6PMu*-Nv!j
{ ca:Vdrw`
try{ M"ZeK4qh
Thread.sleep(nSecond); F^!_!V B
} ;4*mUD6
catch(Exception e) W"D>>]$|u
{ xHlO~:Lc
e.printStackTrace (); p7,dl*'
} +GNXV-S
} [XD3}'Aa
fLuOxYQbf
//日志 )24 1-b V
public static void log(String sMsg) + $Lc'G+:
{ Rab7Y,AA
System.err.println(sMsg); 6I\4Yv$N
} t28 y=nv
`Oe}OSxnT
p$$0**p!`
public static void log(int sMsg) t'HrI-x
{ ,'@t.XP
System.err.println(sMsg); Nkk+*(Z
} jB\Knxm v
} .:Zb~
(l)r.Vj
Jwbb>mB!
/* 1sXVuto
**TestMethod.java T{*!.+E
*/ W"5VqN6v
package NetFox; S8;5|ya
T{lK$j
^7Z.~A y
public class TestMethod { Y-]Ne"+vf
vgKdhN2kI
>2#F5c67
public TestMethod() +QEiY~i
{ ///xx/weblogic60b2_win.exe YvFt*t
try{ 69zMWuY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w[/m:R?eX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ynZfO2kf
SiteFileFetch fileFetch = new SiteFileFetch(bean); dK7BjZTJo
fileFetch.start(); !eD f}~
} =gO4B-[
catch(Exception e){e.printStackTrace ();} 1*OZu.NdK
A7aW]
]J.|XRp/
} !InC8+be
77%I%<#
%"AB\lL.
public static void main(String[] args) :Gf
{ KOhIk*AC'
new TestMethod(); ?rQIUP{D7
} !Gh*Vtd8-
} f+4j ^y}
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