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)); q)vdDdRe_
} zmd,uhNc:
for(int i=0;i<nEndPos.length-1;i++) 4.il4Qqy}i
{ X^;[X~g
nEndPos = nStartPos[i+1]; %;ZWYj`]n
} yN}upYxp
nEndPos[nEndPos.length-1] = nFileLength; FN jT?*
} l3kYfq{";"
} +TzZ
+@*}_%^l"
P7ktr?V0a
//启动子线程 D+edTAQ8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YuufgPE*H
for(int i=0;i<nStartPos.length;i++) eS)2#=
{ uG<VQ2LM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W*?mc2;/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CR8a)X4j#
nStartPos,nEndPos,i); Z3jh-{0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }*eiG
fileSplitterFetch.start(); |m{Q_zAB
} 8 Z|c!QIU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4#hDt^N~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M]9oSi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I#lvaoeN
nEndPos = " + nFileLength); YDh6XD<Z
// fileSplitterFetch[nPos.length-1].start(); }xhat,9
5'iJN$7
Gt;@.jY&
//等待子线程结束 oVi_X98R
//int count = 0; a(Q4*XH4
//是否结束while循环 =2+';Xk\
boolean breakWhile = false; 81?7u!=ic+
1$S;#9PQ
WOqAVd\
while(!bStop) ~{69&T}9
{ Arvxl(R\4
write_nPos(); i>=d7'oR
Utility.sleep(500); "p]Fq,
breakWhile = true; Qa*?iD
_D{zB1d\0
@ qFE6!
for(int i=0;i<nStartPos.length;i++) K&1o!<|
{ u=j|']hp#&
if(!fileSplitterFetch.bDownOver) j5hM|\]
{ Mou@G3
breakWhile = false; +Smt8O<N
break; :CH*~o
} \1`L-lz
} bOIVe
if(breakWhile) %Xm3m0nsv{
break; VrG4wLpLs
\=n0@1Q=>
O<}^`4d
//count++; /WIO@c
//if(count>4) gkxEy5c[
// siteStop(); s=)0y$
} 1|K>V;C
#$\cRLPg
;=rMIi
System.err.println("文件下载结束！"); HbQvu@
} #Bo/1G=
catch(Exception e){e.printStackTrace ();} lo}[o0X
} m3|KIUP
%y@iA91K
-I, _{3.S
//获得文件长度 44s K2
public long getFileSize() Y>OL2g
{ R<r"jOd]
int nFileLength = -1; qg7] YT&
try{ 79.J`}#
URL url = new URL(siteInfoBean.getSSiteURL()); 5f54E|vD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8mjP2
httpConnection.setRequestProperty("User-Agent","NetFox"); iU)-YFO
D+ki2UVt&
NW-l_]k
int responseCode=httpConnection.getResponseCode(); >v4k_JX
if(responseCode>=400) {d|R67~V
{ # SmM5%
processErrorCode(responseCode); ~cE;k@
return -2; //-2 represent access is error zs+[Aco)
} apW0(&\
vBUl6EmWu
!;Mh5*-
String sHeader; ETu7G5?
o?G^=0T
)B d`N^k+
for(int i=1;;i++) ~;ink
{ Ru%: z>Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K;2]c3T
//Utility.log(in.readLine()); ^$][ah
sHeader=httpConnection.getHeaderFieldKey(i); 0m5Q;|mH
if(sHeader!=null) -25#Vh
{ d6lhA7
if(sHeader.equals("Content-Length")) !g? ~<`
{ -Q@jL{Ue
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `I$qMw,@
break; ;qI5GQ {
} rT`D@ I
} #vO3*-hs
else o3H+.u$
break; 1SBc:!2
} qa![oMKc
} )k&pp^q\
catch(IOException e){e.printStackTrace ();} ujcS>XN,1
catch(Exception e){e.printStackTrace ();} fgxsC7P$
c$f|a$$b
`R@24 )
Utility.log(nFileLength); lY}mrb
;F&wGe
^H+j;K{5,
return nFileLength; @LY 5]og
} $,k SR}
O$ i6r]j_
;(w=}s%]+
//保存下载信息（文件指针位置） 6'C!Au
private void write_nPos() ";~}"Yz?[
{ X$JO<@x
try{ {nQ}t }B
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1A23G$D
output.writeInt(nStartPos.length); *D1fSu!
for(int i=0;i<nStartPos.length;i++) z(< E %
{ f{e*R#+&
// output.writeLong(nPos); PF.sM(
output.writeLong(fileSplitterFetch.nStartPos); ~H0~5v F
output.writeLong(fileSplitterFetch.nEndPos); </y V
} aMTY{
output.close(); ]P0DPea
} C#r_qn
catch(IOException e){e.printStackTrace ();} hoC}@8_
catch(Exception e){e.printStackTrace ();} +N[dYm
} bcpH|}[F)
?xf59mY7
yZ&By?.0
//读取保存的下载信息（文件指针位置） Pyi PhOJe
private void read_nPos() \3q{E",\>@
{ m@JU).NKCS
try{ Pi?*rr5WZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =nnS X-x
int nCount = input.readInt(); yh_s(>sh
nStartPos = new long[nCount]; I#l9
nEndPos = new long[nCount]; Tu_dkif'
for(int i=0;i<nStartPos.length;i++) OxF\Hm)(
{ ZNB*Azi
nStartPos = input.readLong(); 3Gn2@`GC
nEndPos = input.readLong(); 9BANCW"
} lGB7(
input.close(); X_ >B7(k
} ^OG^% x"
catch(IOException e){e.printStackTrace ();} V`69%35*@
catch(Exception e){e.printStackTrace ();} >1ZMQgCG
} ^F?H)[0
_0F6mg n
iy tSC
private void processErrorCode(int nErrorCode) MbnV5b:X
{ zi>f436-
System.err.println("Error Code : " + nErrorCode); 62EJ# q[
} [ur/`
mC~W/KReA
RqHxKj
//停止文件下载 e;3$7$n Pv
public void siteStop() Lu:!vTRmw
{ q\#3G
bStop = true; {>FA ~}cX.
for(int i=0;i<nStartPos.length;i++) &P3B
fileSplitterFetch.splitterStop(); B_5q}Bp<
Wr)%C
d;#9xD'
} ^Hq}9OyS9
} kq%`9,XE
//负责部分文件的抓取 6}NvVolr
**FileSplitterFetch.java FA{I S0
*/ uy\YJ.WMQ
package NetFox; 4d]
6%S>~L66
aDZLabRu
import java.io.*; A#1y>k
import java.net.*; iI&SI#; _
=r0!-[XCa
5!nZvv
public class FileSplitterFetch extends Thread { YSrFHVq
ObM5vrEk|
FeV=4tsy
String sURL; //File URL UjKHGsDi4
long nStartPos; //File Snippet Start Position D'nV &m
long nEndPos; //File Snippet End Position ZQBo|8*
int nThreadID; //Thread's ID uaDU+ywL
boolean bDownOver = false; //Downing is over #gN{8Yk>
boolean bStop = false; //Stop identical ]Vwky]d
FileAccessI fileAccessI = null; //File Access interface Zt!l3(*tt
W>@%d`>o5
6AQ;P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #-lk=>
{ [/#n+sz.A
this.sURL = sURL; %7|qnh6
this.nStartPos = nStart; CKBi-q FH
this.nEndPos = nEnd; Mxr#
nThreadID = id; 5h{Hf]A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LnJ7i"Q
} coLn};W2
t*}<v@,
8=nm`7(]
public void run() +^69>L2V
{ JAiV7v4&R
while(nStartPos < nEndPos && !bStop) G,"$Erx
{ vY;Lc
;,4J:zvZdQ
PPq*_Cf
try{ ptDA))7M/
URL url = new URL(sURL); r*p%e\ 3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3:;%@4f
httpConnection.setRequestProperty("User-Agent","NetFox"); b6/:reH{
String sProperty = "bytes="+nStartPos+"-"; Fk9(FOFg
httpConnection.setRequestProperty("RANGE",sProperty); /Cg/Rwl
Utility.log(sProperty); F 1zc4l6
9MYt4
(/KF;J^M
InputStream input = httpConnection.getInputStream(); &0C!P=-p
//logResponseHead(httpConnection); 8v6rS-iHP
`UJW:qqW
{W4t]Ff
byte[] b = new byte[1024]; {(MG: B
int nRead; |y=gp
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x<3vA|o
{ Rw\DJJrz
nStartPos += fileAccessI.write(b,0,nRead); ud#8`/!mq
//if(nThreadID == 1) &1u?W%(Px
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O0{v`|w9+
} RCX4;,DHx
B+Bv(p
qnm9Lw#
Utility.log("Thread " + nThreadID + " is over!"); 3}gK`1Nq1
bDownOver = true; 2mT+@G
//nPos = fileAccessI.write (b,0,nRead); ~w*ojI
} ``z="oD
catch(Exception e){e.printStackTrace ();} y(zU:.
} $?GO|.59
} 7> ]C2!
~ dk1fh
(Z5#;rgem
//打印回应的头信息 UD(#u3z
public void logResponseHead(HttpURLConnection con) `dNb%f>
{ Q$zlxn 7\
for(int i=1;;i++) vSL{WT]m
{ h/VYH(Tj
String header=con.getHeaderFieldKey(i); CFA>
if(header!=null) 2M1mdkP3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ky%%H;
Utility.log(header+" : "+con.getHeaderField(header)); .R"L$V$RU.
else 3gh^a;uC
break; $G}Q}f
} W P&zF$
} "|%fAE
E4.IS=4S
UmuFzw^
public void splitterStop() fh3 6
{ $3Ia+O
bStop = true; )gLasR.1
} hzH5K
iTvCkb48m
n 3]y$wK
} .KSGma6]
?!66yn
`qgJE_GC
/* OgnpzN
**FileAccess.java ?n+\T'f!
*//文件访问(定位，写) q<8HG_
package NetFox; Z}C%%2Iz
import java.io.*; aKy|$ {RC
{cI<4><
,m8*uCf
public class FileAccessI implements Serializable{ "F}Ip&]hAG
Oe!&Jma*>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h:NXO'
RandomAccessFile oSavedFile; !;a<E:
long nPos; i5"q1dRQ
iD`XD\.?
mTgn}rXk
public FileAccessI() throws IOException |{K:.x#^
{ 8gxLL59
this("",0); q}i87a;m
} y^rg%RV
#*/h*GNMs
Z#O3s:`
public FileAccessI(String sName,long nPos) throws IOException hH/O2
{ g1|c?#fwo
oSavedFile = new RandomAccessFile(sName,"rw"); UXJl;Mb
this.nPos = nPos; ~-%A@Lt
oSavedFile.seek(nPos); QAwj]_
} 7A6sSfPUy
}b(e
J5T#}!f
public synchronized int write(byte[] b,int nStart,int nLen) LNE[c
{ xTZ5q*Hqx
int n = -1; uSJP"Lw
try{ >>Di
oSavedFile.write(b,nStart,nLen); mK-:laIL"
n = nLen; 1%`:8
} '7R'fhiO/3
catch(IOException e) eV0S:mit
{ ]IV;>94[
e.printStackTrace (); O :^[4$~
} &/F[kAy
qI^jwl|k
(^9M9+L[i
return n; ;I'/.gW;{
} nL!@#{z
B vc=gW
%5gJ6>@6Z
} 88j ;7
CK</2w+
2A|6o*s"
/* 9(WC#-,
**SiteInfoBean.java KOx#LGz
*/ rg}kxvu
package NetFox; '4sD1LD~}
1_C6KS
]:s|.C%qI
public class SiteInfoBean { NN'<-0~
auW]rwY
O$/swwB!
private String sSiteURL; //Site's URL I+t38un%
private String sFilePath; //Saved File's Path T}[vfIJD
private String sFileName; //Saved File's Name C>dJ:.K%H
private int nSplitter; //Count of Splited Downloading File ooSd6;'
Dt.Wb&V_w
/nFw
public SiteInfoBean() X)OP316yx
{//nSplitter的缺省值为5 VH6|(=8
//default value of nSplitter is 5 <1BK5%?
this("","","",5); o7XRa]O
} #UD
qu+2..3
vP?S0>gh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YO0x68
{ B31-<w
sSiteURL= sURL; ! hr@{CD
sFilePath = sPath; (Nb1R"J`
sFileName = sName; >L`mF_WG
this.nSplitter = nSpiltter; ;_5 =g
~HRWKPb
3yB6]U
} R}9jgB
2z# @:Q
/exl9Ilt]
public String getSSiteURL() M&c1iK\E8
{ kw ^ Sbxm
return sSiteURL; em!R9J.
} {WOfT6y+
G5J ZB7C
%esZ}U
public void setSSiteURL(String value) (1j$*?iGA
{ 5)NBM7h
sSiteURL = value; "mDrJTWa
} t~K!["g
4(GgaQFO?
f+Li'?
public String getSFilePath() C*e[CP@u
{ g 'a?
return sFilePath; D@W3;T^
} =e-aZ0P
x>"JWD
TbAdTmW
public void setSFilePath(String value) XPo'iI-
{ igj@{FN
sFilePath = value; )}\@BtcjA]
} )ZyuF(C&
!>Y\&zA
]mo<qWRc>p
public String getSFileName() Rha3
{ c$:=d4t5$
return sFileName; Nw&}qSN
} W(lKR_pF
[Ms{J!^q
WTv\HI2X !
public void setSFileName(String value) I jztj
{ DLVs>?Y
sFileName = value; H6S vU
} gs8@b5 RSb
9Sl|l.;!
SH$cn,3F8
public int getNSplitter() `oRs-,d|<
{ 8yz((?LrDh
return nSplitter; &|"I0|tJ
} '!h0![OH
h]DECd{
MGyB8(
public void setNSplitter(int nCount) KXA)i5z
{ ::R00gd
nSplitter = nCount; [pFu ]^X
} xp8f
} seU^IC<
yxWMatZ2
=,8Eo"~\
/* KM(9&1/
**Utility.java 9.OwH(Ax7
*/ jy@i(@Z
package NetFox; G$|;~'E
UQ?OD~7
,3--ERf
public class Utility { ,!%R5*?=D
8Y~=\(5>
Cm<j*Cnl
public Utility() S}Y|s]6
{ {r2|fgi
(yAvDyJOn
o"}&qA;
} n.XhK_6n]M
4J 51i*`
//线程睡眠 A1t~&?
public static void sleep(int nSecond) pvQK6r
{ >g"M.gW
try{ [gns8F#H\
Thread.sleep(nSecond); Y0fO.k#C^
} $gl<{{
catch(Exception e) $#ju?B~
{ SP?U@w%}
e.printStackTrace (); chMc(.cN0
} fDEu%fUYZ
} i@R$g~~-D
/<7C[^h{-
//日志 PWN'.HQ
public static void log(String sMsg) ;,vL
{ P9TBQW2G{
System.err.println(sMsg); ^0tf1pV2
} K_+;"G
oSA*~N:
b801OF
public static void log(int sMsg) LUDJPIk
{ |~bR.IA
System.err.println(sMsg); DMcxa.Sd!
} W aGcoj
} X})Imk7&E
.F$|j1y
87pXv6'FQ
/* !MJe+.
**TestMethod.java ,Lun-aMd
*/ ;y~{+{{Ow
package NetFox; "`i:)Et
Tq\~<rEo
d1TdH s\
public class TestMethod { |!?WQ[
s\C8t0C
it\DZGsg
public TestMethod() D_n}p8blT
{ ///xx/weblogic60b2_win.exe ZAX0n!db3
try{ $S=~YzO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yB4H3Q )
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *fH_lG%
SiteFileFetch fileFetch = new SiteFileFetch(bean); pba8=Z
fileFetch.start(); 7.e7Fi{
} 'uKkl(==%
catch(Exception e){e.printStackTrace ();} %t`SSW7I
ZG@M%|>
B&i0j5L
} T4~`e_
Q1nDl
]Q4PbW
public static void main(String[] args) WfDX"rA
{ M,t*nG
new TestMethod(); PwB g
} %nmY:}um
} [l':G]
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