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)); l'"Ici#7Ls
} DA/\[w?J
for(int i=0;i<nEndPos.length-1;i++) ZJ|&t
{ ~4ysg[`
nEndPos = nStartPos[i+1]; $_ k:{?
} qmbhx9V
nEndPos[nEndPos.length-1] = nFileLength; OH vV_
} fZ pUnc
} ob7hNo#
Yr 1k\q
~G8haN4
//启动子线程 I<$m%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F3<Ip~K
for(int i=0;i<nStartPos.length;i++) r-c1_ [Q#
{ r%` |kN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~>5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wZ~eE'zx+
nStartPos,nEndPos,i); F ss@/-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >Gr,!yP
fileSplitterFetch.start(); L7$1rO<
} E>`gj~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )F%zT[Auph
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !R1OSVFp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jg=}l1M"
nEndPos = " + nFileLength); F!ra$5u
// fileSplitterFetch[nPos.length-1].start(); KvuM{UI5
)zvjsx*e=J
k\lU Q\/O5
//等待子线程结束 EL1*@
//int count = 0; (:ij'Zbz
//是否结束while循环 hg}R(.1K=
boolean breakWhile = false; L ^{C4}x=
8DZ OPA
#i[V{J8.p
while(!bStop) +We=- e7
{ RV, cQ K
write_nPos(); S *K0OUq
Utility.sleep(500); \Gz 79VW
breakWhile = true; !9.`zW"40
_:?b-44
>Mk#19j[/
for(int i=0;i<nStartPos.length;i++) $C9['GGR
{ t-$Hti7Lk
if(!fileSplitterFetch.bDownOver) %vjfAdC
{ A,! YXl[
breakWhile = false; U&SgB[QHO
break; P(Q}r7F~(
} '7>Yrzq
} -3&mgd
if(breakWhile) @y{ f>nm
break; '' Pfs<!
V?o%0V
L$ ZZ]?7j
//count++; %3 VToj@`>
//if(count>4) tz`T#9
// siteStop(); t gHXIr}3
} C?lZu\L
Ebytvs,w
m0+'BC{$u
System.err.println("文件下载结束！"); TWTh!
} oAxCI/
catch(Exception e){e.printStackTrace ();} k|[86<&[
} 4+4C0/$Y
fd*<m8
PBp+(o-
//获得文件长度 ^U0)iz
public long getFileSize() z)XIA)i6
{ Q[UYNQ0w
int nFileLength = -1; 0%>_fMaA
try{ 'w~e>$WI
URL url = new URL(siteInfoBean.getSSiteURL()); SbN.z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); anxwK47
httpConnection.setRequestProperty("User-Agent","NetFox"); Qvhz$W[P>
W#lt_2!j
QsH?qI&2jp
int responseCode=httpConnection.getResponseCode(); Xe>
if(responseCode>=400) +U*:WKdI?
{ w]=c^@t_
processErrorCode(responseCode); bx=9XZ9g
return -2; //-2 represent access is error s.9_/cFWB
} i $;y
L(w?.)E
R\,qL-Br
String sHeader; ipn0WQG
,G!mO,DX
x|q|> dPB
for(int i=1;;i++) &VfMv'%x
{ {'1e?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GP;UuQz
//Utility.log(in.readLine()); Y<9]7R(\;
sHeader=httpConnection.getHeaderFieldKey(i); g.d~`R@v
if(sHeader!=null) {2MS,Ua{
{ 31=vUS
if(sHeader.equals("Content-Length")) ~sbn"OS+
{ {;E]#=|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dtd}P~
break; (|U|>@
} NG?-dkD
} )ME'qA3K
else ~Op~~ m
break; diDB>W
} o%.0@W
} {axMS yp;
catch(IOException e){e.printStackTrace ();} +w'He9n
catch(Exception e){e.printStackTrace ();} B7ty*)i?
~5sH`w~vQ
[ %:%C]4
Utility.log(nFileLength); wwVg'V;
/j:fc?yv
UhVJ!NrT
return nFileLength; *J|]E(
} ] R-<v&O
n06Jg+
[|{m/`8C
//保存下载信息（文件指针位置） %"g;K
private void write_nPos() YqNI:znm-
{ OXIy0].b
try{ unN=yeut
output = new DataOutputStream(new FileOutputStream(tmpFile)); )W.Y{\D0
output.writeInt(nStartPos.length); =?s0.(;
for(int i=0;i<nStartPos.length;i++) I4%25=0?
{ WSV[)-=:
// output.writeLong(nPos); MR-cOPn
output.writeLong(fileSplitterFetch.nStartPos); IM$I=5ye
output.writeLong(fileSplitterFetch.nEndPos); +3%i7
} q;#:nf"
output.close(); A!.* eIV|
} \bzT=^Z;2
catch(IOException e){e.printStackTrace ();} 3E]IEf
catch(Exception e){e.printStackTrace ();} i8H!4l
} "'\f?A9
]n$&|@
2#g4R
//读取保存的下载信息（文件指针位置） 9d1 Gu"
private void read_nPos() :MbD=sX
{ EaXDY<
try{ ("-`Y'"K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \B1<fF2
int nCount = input.readInt(); %eDJ]\*^X
nStartPos = new long[nCount]; c3G&)gU4q
nEndPos = new long[nCount]; dpI9DzA;
for(int i=0;i<nStartPos.length;i++) t?404
{ gP 6`q
nStartPos = input.readLong(); sksop4gu5
nEndPos = input.readLong(); `UH 1B/
} hDc)\vzr
input.close(); W99Hq1W;r
} 96.Vm*/7
catch(IOException e){e.printStackTrace ();} 6h_OxO&!U
catch(Exception e){e.printStackTrace ();} 1ps_zn(
} .e8S^lSl
P<GHX~nB
SP |R4*KY
private void processErrorCode(int nErrorCode) `.8#q^
{ *2tG07kI
System.err.println("Error Code : " + nErrorCode); <{yQNXf[
} #w:6<$
q\gvX 76a
,H+LE$=
//停止文件下载 7gY^aMW
public void siteStop() Ul?92
{ t4E=
bStop = true; YDMimis\H5
for(int i=0;i<nStartPos.length;i++) +m8gS;'R4
fileSplitterFetch.splitterStop(); Md4JaFA(
d3|oKP6
Q]]5\C.
} zrJ/Fs+s
} zxr|:KC ?&
//负责部分文件的抓取 Qy+&N*k>
**FileSplitterFetch.java ugI9rxT]Kv
*/ 0{GpO6!
package NetFox; 5V{zdS=
G$"$k=[
[Nn ?:5"
import java.io.*; mtON dI
import java.net.*; o?$B<Cb"
iS"(
"x*5g*k
public class FileSplitterFetch extends Thread { G#pRBA^
1E*No1
6SIk,Isy8
String sURL; //File URL NZyGC Vh@
long nStartPos; //File Snippet Start Position z$>_c"D
long nEndPos; //File Snippet End Position PmGW\E[ni
int nThreadID; //Thread's ID v3i]z9`
boolean bDownOver = false; //Downing is over W5_:Q@
boolean bStop = false; //Stop identical RG)!v6
FileAccessI fileAccessI = null; //File Access interface K;u<-?En
L.uX
xnW3,:0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9$z|kwU
{ aF9p%HPDw
this.sURL = sURL; DUk&`BSJ
this.nStartPos = nStart; 4X@ <PX5
this.nEndPos = nEnd; rSUarfZ<
nThreadID = id; }jQxwi)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X4:\Shb97
} 1XAXokxj
gJ_{V;R
w~NQAHAvo
public void run() xm}9(EJ
{ v>FsP$p4yE
while(nStartPos < nEndPos && !bStop) @?$x
{ +mQMzZZTZ
?mJNzHrq;
ze<Lc/;X~
try{ i(^&ZmG
URL url = new URL(sURL); 0^41dfdE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8,Jjv*
httpConnection.setRequestProperty("User-Agent","NetFox"); 9Ij=~p]p
String sProperty = "bytes="+nStartPos+"-"; W=fw*ro
httpConnection.setRequestProperty("RANGE",sProperty); Jhclg0q
Utility.log(sProperty); o5UM)g
@)A)cBv#
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InputStream input = httpConnection.getInputStream(); QxRT%;'Zh]
//logResponseHead(httpConnection); :}\w2W E[
&_-,Nxsf
v+. n9
byte[] b = new byte[1024]; 'D ,efTq
int nRead; B{UL(6\B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cFcn61x-
{ -}u=tiNG
nStartPos += fileAccessI.write(b,0,nRead); L|hdV\
//if(nThreadID == 1) _i_^s0J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C&\MDOjx
} zn| S3c
q\2q3}n
m0}Pq{g
Utility.log("Thread " + nThreadID + " is over!"); kvWP[! j?)
bDownOver = true; _4eSDO[h
//nPos = fileAccessI.write (b,0,nRead); ldd|"[Ds
} : GVyY]qBU
catch(Exception e){e.printStackTrace ();} ~HWH2g
} Y>Oh]?
} rI/;L<c
2YT1]x 3
BE`{? -G
//打印回应的头信息 >?-etl
public void logResponseHead(HttpURLConnection con) F1m 1%
{ (v<l9}!
for(int i=1;;i++) eIZ7uSl
{ p:*)rE
String header=con.getHeaderFieldKey(i); %sd1`1In
if(header!=null) ZDMv8BP7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]q#w97BxiJ
Utility.log(header+" : "+con.getHeaderField(header)); N4]Sp v
else h(M_ K
break; s|p,UK
} DdUT"%
} MK"p~b0->
BHmmvbM#Qm
u'Od~x^z
public void splitterStop() _/FpmnaY
{ }XOTK^YA
bStop = true; QCm93YZs6E
} Z2Q'9C},m
Ge'[AhA
caG5S#8-"
} wSy|h*a,
Ox| ?
prIPPeMdz
/* }s9eRmJs
**FileAccess.java )Y@E5Tuk>
*//文件访问(定位，写) H0!LiazA>
package NetFox; ^bD)Tg5K
import java.io.*; o\TXWqt
L<7KmN4VX
3np |\i
public class FileAccessI implements Serializable{ 5`_UIYcI
9$ VudE>;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1<9=J`(H
RandomAccessFile oSavedFile; sKg IKYG}T
long nPos; =&_Y=>rA]0
+.czj,Sq
Z2t'?N|_
public FileAccessI() throws IOException n_ 3g
{ MD4RSl<F
this("",0); T{CCZ"Fv
} qS9z0HLE
4MFdhJoN
> w-fsL
public FileAccessI(String sName,long nPos) throws IOException 'K!u}py
{ 6L/`
oSavedFile = new RandomAccessFile(sName,"rw"); su}n3NsJ
this.nPos = nPos; J<9;Ix8R
oSavedFile.seek(nPos); )yTBtYw3
} 4[XiD* *
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w/oXFs&FK
public synchronized int write(byte[] b,int nStart,int nLen) 2ophh/]
{ G m~2s;/
int n = -1; *SmR|Qy
try{ ;irAq|
oSavedFile.write(b,nStart,nLen); Hob n{E
n = nLen; .4cVX|T
} N<N uBtkA
catch(IOException e) }2]m]D@%7
{ 7Eo;TNbb
e.printStackTrace (); OpLo[Y\
} NY3/mS3w
>(\Z-I&YQ
=K;M\_k%y
return n; 0F-%C>&g
} ra|Ku!
W @]t
8#ZF<BY
} V6!1(|
%0_}usrsk
:>*0./hG
/* M\D25=(
**SiteInfoBean.java 8D&yFal
*/ d",VOhW7)S
package NetFox; RQ;}+S
gkFw=Cd
D16w!Mnz{K
public class SiteInfoBean { 43s8a
~F.kgX
Oq[YbQ'GE
private String sSiteURL; //Site's URL +lhnc{;WJv
private String sFilePath; //Saved File's Path y7T<Auue`
private String sFileName; //Saved File's Name HXb_k1n
private int nSplitter; //Count of Splited Downloading File 1'!%$D
6FFM-9*|[
fn, YH
public SiteInfoBean() "Ky&x$dje
{//nSplitter的缺省值为5 |lMc6C
//default value of nSplitter is 5 M-/2{F[
this("","","",5); sf Zb$T J
} 4O7 {a
[{.9#cQ"
}t0JI3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PM3fJhx
{ ]2rCn};
sSiteURL= sURL; W=I~GhM
sFilePath = sPath; VK% j45D`
sFileName = sName; 4"s/T0C
this.nSplitter = nSpiltter; 3|(3jIa
|4!G@-2V:I
OWZ;X}x
} v9 8s78
A2''v3-h8
kZ'wXtBYe
public String getSSiteURL() $msf~M*
{ 5l]qhi3f
return sSiteURL; 7X8n|NZRH7
} J@qwz[d i
rw#?NI:
Z@i,9 a
public void setSSiteURL(String value) [6CWgQ%Ue
{ #ds@!u+&
sSiteURL = value; M%2w[<-8c
} h]WW?.
I^m9(L4%
=a6e*f
public String getSFilePath() Hv</Xam
{ Mo]
return sFilePath; a6'T]DW0W
} pg3h>)$/
>g,i"Kg
!H(V%B%
public void setSFilePath(String value) yc0_7Im?
{ ^-,@D+eW
sFilePath = value; W];l[D<S*
} Wb;D9Z
9-EdT4=r,
*z__$!LR
public String getSFileName() 0W,.1J2*
{ oG=4&SQ
return sFileName; s,~g| I\
} Jm-bE 8b
Svm'ds7>
R T/)<RT9
public void setSFileName(String value) ddw^oU
{ (f
sFileName = value; vA*Q}]Ov
} bf6:J `5Z
> mEB,
pQk@ +r
public int getNSplitter() '1b4nj|<m
{ 9 OZXs2~x
return nSplitter; yE|hA2G?0
} j>Cp4
!mK}Rim~
Z |<
public void setNSplitter(int nCount) hx8.
{ _c,{}sn
nSplitter = nCount; c1Hp
} yw*| HT
} KB8_yo{y
uuYeXI;
#dkSAS
/* 0D&-BAzi
**Utility.java 7-d.eNQl
*/ apWv+A
package NetFox; UP*5M
Dmr3r[
r+,JM L
public class Utility { C%AN4Mo
.yQ<
8p PQ
public Utility() YtA<4XHU
{ K/z2.Npn
xPzBbe
a!\^O).pA
} S+GW}?!
r}-vOPn`E
//线程睡眠 hQaa"U7[
public static void sleep(int nSecond) >)VWXv0
{ ;:'ABfs
try{ a"phwCc"%
Thread.sleep(nSecond); JdX!#\O
} Q$A;Fk}-
catch(Exception e) 5W(`lgVs,
{ ]fJ9.Js
e.printStackTrace (); >f(M5v(D\
} 'SKq<X%R;
} LrdX^_,nt
hHyB;(3~
//日志 Dp^6|T*HU
public static void log(String sMsg) g:Fo7*i
{ e5m]mzF@
System.err.println(sMsg); -gpHg
} <=@6UPsn2
[uFv_G{H
cX|(/h,W/
public static void log(int sMsg) q0(-"}2l
{ `Db%:l^e
System.err.println(sMsg); g|5cO3m0'
} /~P4<1
} ja^
8r48+_y3u
?6 "B4%7b
/* UDV6 ##$
**TestMethod.java qm"AatA
*/ Xvxj-\ -
package NetFox; U[NQ"
;ApldoMi
DS0:^TLI
public class TestMethod { T*](oA@
Gg6<4T1
4\m#:fj %
public TestMethod() 3<}r+,j
{ ///xx/weblogic60b2_win.exe )V9wU1.
try{ F,@uYMQs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F\-oZ#g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7$"n.cr :
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4']eJ==OH
fileFetch.start(); Je=k.pO1
} 3mT6HGSKR
catch(Exception e){e.printStackTrace ();} UGQHwz
sNsWz.DLT#
>!%+)
} %h&F
5N$O
Nj+gSa9
public static void main(String[] args) d ZxrIWx
{ W4]jx]
new TestMethod(); %( #kJZ
} SFVqUg3"Z
} ,XsBm+Q(
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