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)); V\M!]Nnxr
} >ya-
for(int i=0;i<nEndPos.length-1;i++) vs0H^L
{ ma-Y'
nEndPos = nStartPos[i+1]; pTX'5
} ='bmjXu
nEndPos[nEndPos.length-1] = nFileLength; k+R?JWC:
} yxP?O@(
} \lbiz4^>
\IZ4(Z
(z1%lZ}(
//启动子线程 ~Ro:mH:w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UH^wyKbM
for(int i=0;i<nStartPos.length;i++) 2#:]%y;\
{ 13&>w{S}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K<L%@[gi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^$Io;*N4
nStartPos,nEndPos,i); e$^!~+J7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y0&HXX#\
fileSplitterFetch.start(); ]xLb )Z
} >scS wT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F+$@3[Q`N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @[b:([
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ty< tv|p
nEndPos = " + nFileLength); .sR&9FH
// fileSplitterFetch[nPos.length-1].start(); z3jzpmz
S,tVOxs^
8m[L]6F(-z
//等待子线程结束 s=~7m.m
//int count = 0; yoY)6cn@
//是否结束while循环 *,[=}v1
boolean breakWhile = false; u4+uGYr*@
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4"X>_Nt6
while(!bStop) E|4XQ|B@
{ 2V"gqJHv
write_nPos(); n`KXJ?t
Utility.sleep(500); |AfQ_iT6c
breakWhile = true; \\G6c4fC
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~m|?! ]n
for(int i=0;i<nStartPos.length;i++) ^$,kTU'=
{ SyVbCj
if(!fileSplitterFetch.bDownOver) &?`&X=Q
{ i|^`gly
breakWhile = false; :lQjy@J
break; +\Mm (Nd
} UO!6&k>c
} n03SXaU~V
if(breakWhile) g5|\G%dOt
break; #DRtMrfat
2P=~3g*
bfI -!,
//count++; u R%R]X
//if(count>4) Jo(}#_y?
// siteStop(); l(#Y8
} %y\7
kGqf@ I+
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System.err.println("文件下载结束！"); [k=9 +0p
} }Z?[Ut
catch(Exception e){e.printStackTrace ();} Tc(v\|F,
} r=||sZs
BBJ]>lQ
:::f,aCAu
//获得文件长度 +\oHQ=s>}\
public long getFileSize() molowPI
{ uv!qE1z@':
int nFileLength = -1; ~S>ba']
try{ .*f4e3
URL url = new URL(siteInfoBean.getSSiteURL()); #R PB;#{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L0VR(
httpConnection.setRequestProperty("User-Agent","NetFox"); HPdwx V
'htA! KHF
'^(v8lCu
int responseCode=httpConnection.getResponseCode(); =pOY+S|
if(responseCode>=400) *K.7Zf0
{ [f(^vlK
processErrorCode(responseCode); ~wg^>!E
return -2; //-2 represent access is error Q4:r$ &
} 0a%ui2k
9S1V!Jp
64>[pZF8
String sHeader; w&cyGd D5
uBkny;
xa0%;nFKe
for(int i=1;;i++) TXl9c6
{ c]R![sa
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3&Rqz9W
//Utility.log(in.readLine()); RX\O'Zwlj
sHeader=httpConnection.getHeaderFieldKey(i); @N{Ht)1r
if(sHeader!=null) |+~2sbM
{ q;PzB4#
if(sHeader.equals("Content-Length")) 3D dG$@
{ (3r,PS@Qq@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G ]By_
break; >t}D5ah
} 4:PP[2?
} 3'e 4{
else &.4_4"l(
break; km^+ mK
} ,VsCRp
} j5GZ;d?
catch(IOException e){e.printStackTrace ();} M%^laf
catch(Exception e){e.printStackTrace ();} 6lAo`S\)eX
)9Ojvp=#r:
^!Jm/-
Utility.log(nFileLength); <Pt\)"JA
s9bP6N!,
)II,HT-LY
return nFileLength; *)D*iU&
} kP@OIhRe
OSIp
R0d|j#vP
//保存下载信息（文件指针位置） S IK{GWX
private void write_nPos() M=`Se&-M
{ O;?~#E<6w
try{ Bcon4
output = new DataOutputStream(new FileOutputStream(tmpFile)); I>Yp=R
output.writeInt(nStartPos.length); 6l7a9IJ
for(int i=0;i<nStartPos.length;i++) bLF0MVLM
{ v[3sg2.
// output.writeLong(nPos); d`7] reh
output.writeLong(fileSplitterFetch.nStartPos); 8E%*o
output.writeLong(fileSplitterFetch.nEndPos); x,_Ucc.
} |YFlJ2w
output.close(); uhLmyK
} +0 |0X {v
catch(IOException e){e.printStackTrace ();} }TL"v|ny6;
catch(Exception e){e.printStackTrace ();} Tou~U[V+
} hI{Yg$H1
Lpf=VyqC
?EAqv]
//读取保存的下载信息（文件指针位置） (Z +C
private void read_nPos() /U]5#'i
{ dD<kNa}2
try{ W^Y(FUy~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W%cPX0
int nCount = input.readInt(); !{lb#
nStartPos = new long[nCount]; d6&tz!f
nEndPos = new long[nCount]; 9Wrclai
for(int i=0;i<nStartPos.length;i++) 0pOha(,~
{ `VN<6o(
nStartPos = input.readLong(); nCB3d[/B
nEndPos = input.readLong(); *?fBmq[j
} 1<|I[EI
input.close(); P[i/o#
} P@?CQvMx
catch(IOException e){e.printStackTrace ();} ':$a6f &T
catch(Exception e){e.printStackTrace ();} eqCB2u"Jq
} R"([Y#>m
}2oJ
_0E,@[
private void processErrorCode(int nErrorCode) xII!2.
{ ]XyJ7esg
System.err.println("Error Code : " + nErrorCode); i`L66uV
} {rLOAewr
Su#1yw>
+-d>Sl (
//停止文件下载 RBwV+X[B
public void siteStop() ^yTN(\9
{ >.4Sx~VH2
bStop = true; Q.\ovk~,a
for(int i=0;i<nStartPos.length;i++) xRN$cZC
fileSplitterFetch.splitterStop(); I5?LD=tt
9~I WGj?
]:fHvx_?`7
} JN)t'm[kyE
} W:J00rsv=`
//负责部分文件的抓取 MJ08@xGa
**FileSplitterFetch.java xpwzzO*U
*/ cTp+M L
package NetFox; bxq`E!]
cgOoQP/#
K? k`U,
import java.io.*; FG\?_G
import java.net.*; %xz02$k
sNVD"M,
h+@t8Q;gGw
public class FileSplitterFetch extends Thread { \gpKQt0
! +7ve[z
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String sURL; //File URL "RA$Twhj
long nStartPos; //File Snippet Start Position OQvJdjST
long nEndPos; //File Snippet End Position n0q(EQy1U
int nThreadID; //Thread's ID P_g
boolean bDownOver = false; //Downing is over |0-L08DW
boolean bStop = false; //Stop identical $49tV?q5
FileAccessI fileAccessI = null; //File Access interface } _z~:{Y
6:pN?|=6X
nE84W$\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9qA_5x%"%u
{ }=FQKqtC
this.sURL = sURL; fHi+PEbR
this.nStartPos = nStart; PV2904
this.nEndPos = nEnd; *TkABUL
nThreadID = id; NQ!F`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u 36;;z
} S\m]ze
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/([aD~.
public void run() x;Q2/YZ#
{ uItKsu
while(nStartPos < nEndPos && !bStop) w5Xdq_e3
{ <T]kpP<lC
)FLpWE"e-
;r']"JmF,
try{ [>86i
URL url = new URL(sURL); {w++)N2sh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RP9||PFS~~
httpConnection.setRequestProperty("User-Agent","NetFox"); |IvX7%*]~
String sProperty = "bytes="+nStartPos+"-"; F/Xhm91^
httpConnection.setRequestProperty("RANGE",sProperty); &Is%I<'o
Utility.log(sProperty); vI@8DWs
)LG/n
{ex]_V>
InputStream input = httpConnection.getInputStream(); p pq#5t^[)
//logResponseHead(httpConnection); 6BnjT
xT/&'$@{)
W+E2({
byte[] b = new byte[1024]; .B*)A.
int nRead; zl5S)/A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3^Y-P8.zdB
{ ^8iy(
nStartPos += fileAccessI.write(b,0,nRead); ITV}f#
//if(nThreadID == 1) hGeRM4zVZZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vY6|V$
} xjpW<-)MLf
53QP~[F8R]
'Vd>"ti
Utility.log("Thread " + nThreadID + " is over!"); ?)&TewP
bDownOver = true; vKeK]
//nPos = fileAccessI.write (b,0,nRead); 7^F?key?
} /<@tbZJ*8
catch(Exception e){e.printStackTrace ();} !IS,[
} c LJCLKJ
} ?m6E@.{
]2jnY&a5
G r)+O
//打印回应的头信息 ]rS+v^@QH
public void logResponseHead(HttpURLConnection con) C1J'. !
{ sAb|]Q((
for(int i=1;;i++) H;6V
{ o>YRKb
String header=con.getHeaderFieldKey(i); 2-4%h!
if(header!=null) qA30G~S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O_ cK4
Utility.log(header+" : "+con.getHeaderField(header)); 0U<9=[~q7@
else uD"Voh|]=
break; =ZQIpc
} IYWD_}_ $
} A{QS+fa/
[o~w>,a
H4N==o
public void splitterStop() &Ru6Yt0W
{ Dz?F,g_
bStop = true; _?ym,@}#
} TsQMwV_h
MAXdgL[]
Z8x(_ft5
} C9h8d
}7V/(K
z)26Ahm TV
/* o|+tRl
**FileAccess.java F~B8XUa3
*//文件访问(定位，写) xiI!_0'
package NetFox; (.c?)_G,
import java.io.*; yVL~SH|
[;(|^0
&^EkM
public class FileAccessI implements Serializable{ X7G6y|4;w
{XVSHUtw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eg3{sDv,
RandomAccessFile oSavedFile; (w.B_9#
long nPos; Pw")|85
g%Z;rDfi
<ANKoPNie
public FileAccessI() throws IOException #&2mu
{ DeUDZL%/
this("",0); ((y+FJH
} >4Lb+]
V{npK(
?$ 3=m)s
public FileAccessI(String sName,long nPos) throws IOException b7$?'neH/.
{ CB~&!MdMr
oSavedFile = new RandomAccessFile(sName,"rw"); &(K*TB|Om
this.nPos = nPos; f /jN$p
oSavedFile.seek(nPos); Gqs8$[o
} SbB5J> >7J
cIgF]My*D@
1G\ugLm
public synchronized int write(byte[] b,int nStart,int nLen) yY1&hop
{ =Rui
int n = -1; ''Hq-Ng
try{ (i`DUF'#y
oSavedFile.write(b,nStart,nLen); Eb.{M
n = nLen; MG~^>
} +h =lAHn&
catch(IOException e) {DpZg",H-
{ i_MDLS>-
e.printStackTrace (); p\(%bO
} QKVZ![Y!s
}, ]W/
AIE)q]'Q
return n; QoqdPk#1
} htaB!Q?V
0q/g:"|j
,xGlWH wrY
} P6X 4m(t
.G^.kg ,
Cc=`:ED+
/* 9 Hm!B )Y
**SiteInfoBean.java Jzr(A^vwo
*/ U $+rlw}
package NetFox; l_8t[
s?=J#WV1y
_h5@3>b3r
public class SiteInfoBean { 5!AzEB
i$ Zhk1
/_LUys/0
private String sSiteURL; //Site's URL ~2pctqMA
private String sFilePath; //Saved File's Path >iq^Ts
private String sFileName; //Saved File's Name RY*6TYX!
private int nSplitter; //Count of Splited Downloading File I3SLR
u~G,=n
ZJ!/49c*>
public SiteInfoBean() ^UJO(
{//nSplitter的缺省值为5 r:u5+A
//default value of nSplitter is 5 JK_sl>v.7
this("","","",5); zRB1V99k
} bJ9>,,D
GwpJxiFgk
0.?|%;^ib
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FO*Py)/rX
{ D[U5SS!)
sSiteURL= sURL; /P,J);Y
sFilePath = sPath; ed&,
sFileName = sName; MJK L4 G
this.nSplitter = nSpiltter; dLv\H&
ecr pv+
#MI}KmH
} [/#;u*n
z7J#1q~:yY
]92@&J0w
public String getSSiteURL() sR#( \
{ 1(C%/g#"
return sSiteURL; 8TuOf(qE
} Z,ag5 w`]L
C,K P!B{
Zr`:A$
public void setSSiteURL(String value) N2C^'dFj
{ +`\C_i-
sSiteURL = value; 8on2BC2
} p7|~x@q+
:U?Kwv8s
Q~uj:A]n<
public String getSFilePath() G:f]z;Xdp
{ o-/Xa[yC
return sFilePath; [t,7H
} W|~Ehg
U{HJNftdpm
sHKT]^7
public void setSFilePath(String value) ca-|G'q
{ 1J^{h5?lU
sFilePath = value; -p9|l%W
} g,9o'fs`x
J8(v65
U2!9Tl9".
public String getSFileName() {ImZ><xe/
{ wz;IKdk[
return sFileName; Dk8" H>*
} .|cQ0:B[
7+@:wX\
^cd+W?
public void setSFileName(String value) 4K:p
{ d&t|Y:,8
sFileName = value; AOhsat;O`
} p.&FK'&[0
8L.Y0_x
]M>mwnt+
public int getNSplitter() N3i}>Q)B
{ 1[/X$DyaK
return nSplitter; r=<,`_@Y
} p)d'yj
S_aml
03[(dRK>=
public void setNSplitter(int nCount) P)ZGNtO9fG
{ K5'@$Km
nSplitter = nCount; W~FcU+a
} .\qZkk}2l
} <[kdF")
rs'~' Y
IC37f[Q
/* DTPYCG&%
**Utility.java L<*wzl2Go
*/ or>5a9pj
package NetFox; *tO7A$LDT
nO2-fW:9]
V6Z2!Ht
public class Utility { -@e9!/GP,
r@^h,
5q}680s9+
public Utility() u:NSPAD)
{ UVA|(:
x-mRPH
u-yQP@^H
} %jim] ]<S[
Fz~-m#Ts
//线程睡眠 R"VmN2
public static void sleep(int nSecond) H5{d;L1[
{ SX$v&L<
try{ ZWxq<&Cg
Thread.sleep(nSecond); rhsSV3iM
} Z@=#ry
catch(Exception e) CFkM}`v0
{ *dL!)+:d
e.printStackTrace (); E_MGejm@
} G(EiDo&
} SZea[~&
1|Us"GQ(n
//日志 &AG,]#
public static void log(String sMsg) ?`3`azfM
{ #B_ ``XV
System.err.println(sMsg); 0Ou`&u
} ?n8gB7(FA
;gu_/[P
U8PSJ0ny
public static void log(int sMsg) EQET:a:g
{ JFIUD{>fp
System.err.println(sMsg); YcBY[i0
} kTL{?-
} S9U,so?
]4ya$%A
.'saUcVg:
/* pZ}4'GnZI
**TestMethod.java eR4%4gW)
*/ }PTYNidlR
package NetFox; RHZ5f0b4L
ML^c-xY(
TXWi5f[
public class TestMethod { a2 e-Q({
N=YRYUo
b)tvXiO1>
public TestMethod() 3i/$YX5@
{ ///xx/weblogic60b2_win.exe <b~KR8
try{ %qfql
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R_e{H^pY^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PMebn$(
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^F"Q~?D)
fileFetch.start(); Fc%@
} ggR@& \
catch(Exception e){e.printStackTrace ();} :n4?
C0eP/d
_@3@_GE
} nlQ<Aa-%
C0|<+3uND=
'5\7>2fI
public static void main(String[] args) /p+ (_Y
{ 7@NAky(
new TestMethod(); 7aUk?Hf
} {+_pyL
} "T|%F D&[
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