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)); a$'=a09
} <Q?X'.
for(int i=0;i<nEndPos.length-1;i++) HESORa;
{ -!z,t7!
nEndPos = nStartPos[i+1]; [#6Eax,j
} &5F@u IA
nEndPos[nEndPos.length-1] = nFileLength; l*C(FPw4
} X3;|h93.a
} or1D 6*'
Ok&u4'<
)mMHwLDwH
//启动子线程 q!+m, !M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .ahYjn
for(int i=0;i<nStartPos.length;i++) ;.P9t`*
{ ]za1=~[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +gQoYlso
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mOvwdRKn
nStartPos,nEndPos,i); +c^[[ K"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hZ@Wl6FG;
fileSplitterFetch.start(); Fi^Q]9.@{
} @.Pe.\Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -Am~CM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]MXeWS(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -h<Rby
nEndPos = " + nFileLength); SMdQ,n1]
// fileSplitterFetch[nPos.length-1].start(); amK.H"
b:uMON,H
_A%8oYS
//等待子线程结束 >O:j.(*!
//int count = 0; @4N@cM0
//是否结束while循环 K)C9)J<
boolean breakWhile = false; %l7|+%M.{
n/fMq,<8
1]uHaI(
while(!bStop) _n;V iQMu
{ 3G7Qo
write_nPos(); OK}+:Y
Utility.sleep(500); Zn`vL52_
breakWhile = true; HXTZ`'Rv
?lYi![.o
b{o%`B*
for(int i=0;i<nStartPos.length;i++) ]"< `^
{ \Q+<G-Kb.
if(!fileSplitterFetch.bDownOver) Gmi$Nl!~
{ oX9rpTi
breakWhile = false; wv8WqYV
break; sinnHQ
} *VFUC:
} |-c)OS3#D
if(breakWhile) /~Q2SrYH
break; yI 6AafS~
W c"f
'bpx
//count++; *hp3w
//if(count>4) <-:gaA`KM
// siteStop(); [p+6HF
} e!67Na0X(
9 L{JU
NyTv~8A`)
System.err.println("文件下载结束！"); #Cda8)jl(
} nZbfc;da
catch(Exception e){e.printStackTrace ();} b[3K:ot+
} :b&O{>M]Y
5X5&(S\
8uR4ZE*
//获得文件长度 `eat7O
public long getFileSize() Vb`m3
{ }-:s9Lt
int nFileLength = -1; OA??fb,b
try{ BiQ7r=Dd.
URL url = new URL(siteInfoBean.getSSiteURL()); MXbt`]`_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0\*6UH
httpConnection.setRequestProperty("User-Agent","NetFox"); E5P?(5Nv
# 4AyA$t
'1[}PmhD
int responseCode=httpConnection.getResponseCode(); +IiL(\ew
if(responseCode>=400) 'mz _JM
{ 0?]*-wvp
processErrorCode(responseCode); 7ZbnG@s7
return -2; //-2 represent access is error > !thxG/_
} T=|oZ
'G!w0yF
\h DH81L
String sHeader; n"'1.
Htseu`>_$
0i2ZgOJ
for(int i=1;;i++) DbdxHuKa>
{ !YlyUHD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jj,Y:
//Utility.log(in.readLine()); FfnW
sHeader=httpConnection.getHeaderFieldKey(i); OQ>r;)/
if(sHeader!=null) >W= 0N(
{ /h=:heS4$
if(sHeader.equals("Content-Length")) 1'dL8Y
{ F^Yt\V~T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]~:9b[G2
break; URbu=U
} @tvAI2W
} ^Tbw#x]2
else 8}FZ1h2 4
break; ZW$PJmz
} MXWCYi
} 2YD;Gb[8
catch(IOException e){e.printStackTrace ();} v7+f@Z:N*
catch(Exception e){e.printStackTrace ();} IG?044Y
$*ujX,}xG
ITa8*Myj
Utility.log(nFileLength); N`7) 88>w
LHjGlBy
u:r'&#jb~@
return nFileLength; *xxG@h|5n
} z\Vu`Yz
w:l/B '%]Y
^lCys
//保存下载信息（文件指针位置） KS($S(Fi
private void write_nPos() 9K*yds
{ +;7Rz_.6f
try{ fS50
output = new DataOutputStream(new FileOutputStream(tmpFile)); _{z.Tu
output.writeInt(nStartPos.length); @G0k+
for(int i=0;i<nStartPos.length;i++) !BD+H/A.{
{ b&BSigrvou
// output.writeLong(nPos); $+eDoI'f
output.writeLong(fileSplitterFetch.nStartPos); ViqcJD
output.writeLong(fileSplitterFetch.nEndPos); )jbYWR*&
} rWKc,A[
output.close(); q.6$-w
} h$)},% e
catch(IOException e){e.printStackTrace ();} Sr1xG%;|/
catch(Exception e){e.printStackTrace ();} *k:Sg*neVq
} KN>U6=WN
GQXN1R
V3O<l}ak
//读取保存的下载信息（文件指针位置） A+d&aE}3V
private void read_nPos() `z<k7ig
{ pj.}VF!d
try{ gR)T(%W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ydOJ^Yty
int nCount = input.readInt(); vy?Zz<c;
nStartPos = new long[nCount]; <$)F_R~T3
nEndPos = new long[nCount]; 2 F3U,}
for(int i=0;i<nStartPos.length;i++) P#5&D*`}h
{ V=}AFGC85
nStartPos = input.readLong(); {S4^;Va1
nEndPos = input.readLong(); t(FIBf3
} aW-'Jg=@H^
input.close(); >gqM|-uY
} J8[N!qDCj
catch(IOException e){e.printStackTrace ();} }r:H7&|&
catch(Exception e){e.printStackTrace ();} p`ai2`qC`
} [UN`~
.c~`{j}
ng$`<~=)\
private void processErrorCode(int nErrorCode) dx{ZG'@aH
{ 9$F '*{8
System.err.println("Error Code : " + nErrorCode); g7G=ga
} GmoY~}cg~
"|&xUWJ!)
8Qtd,
//停止文件下载 O?|st$g
public void siteStop() $ftcYBZa
{ [ix45xu7
bStop = true; sV{M#UF2
for(int i=0;i<nStartPos.length;i++) HhkubG)\
fileSplitterFetch.splitterStop(); b=<xzvy
V_*TY6
.\1{>A
} XKqUbi
} o<T_Pjp
//负责部分文件的抓取 4OLq
**FileSplitterFetch.java QF 2Eg
*/ ln}2
package NetFox; ^DZ(T+q,
@&!HMl
,<]X0;~oB
import java.io.*; {bB;TO<b`
import java.net.*; lTOO`g
S7SD$+fX
$agd9z,&m
public class FileSplitterFetch extends Thread { noz&4"S.{
7U_~_yb
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String sURL; //File URL _\M:h+^
long nStartPos; //File Snippet Start Position OEc$ro=m*
long nEndPos; //File Snippet End Position :n36}VG|
int nThreadID; //Thread's ID >% a^;gk(
boolean bDownOver = false; //Downing is over Wx&gI4~
boolean bStop = false; //Stop identical L$*sv.
FileAccessI fileAccessI = null; //File Access interface S0+nQM%
$7%e|0jC
{L 7O{:J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X.V6v4
{ kae&,'@JF
this.sURL = sURL; nRKh|B)
this.nStartPos = nStart; h"<-^=b
this.nEndPos = nEnd; &sJZSrk|
nThreadID = id; M7rVH\:[-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ic_>[E?k
} (h;4irfX
/$v0Rq9
Ik_u34U
public void run() 8RC7Ei
{ rOC2 S(m
while(nStartPos < nEndPos && !bStop) d\Q~L 3x
{ Zi$v-b*<
$@y<.?k>UP
EN^C'n
try{ A*)G. o:
URL url = new URL(sURL); A8bDg:G1i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;E? Z<3{
httpConnection.setRequestProperty("User-Agent","NetFox"); ]=T`8)_r)
String sProperty = "bytes="+nStartPos+"-"; k.b->U
httpConnection.setRequestProperty("RANGE",sProperty); DpG|Kl|d
Utility.log(sProperty); 7;H!F!K]
+z/_'DE
gc|?$aE
InputStream input = httpConnection.getInputStream(); 4Eq$f (QJ
//logResponseHead(httpConnection); |fYr*8rH
dq$H^BB+>
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byte[] b = new byte[1024]; dD _(MbTt
int nRead; uh`W} n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E3X6-J|
{ NbPv>/r
nStartPos += fileAccessI.write(b,0,nRead); 34lt?6%j
//if(nThreadID == 1) Qo7]fnnaV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /ekeU+j
} 1+\ZLy!5:
04eE\%?
. e' vc
Utility.log("Thread " + nThreadID + " is over!"); $f`\TKlN
bDownOver = true; mx`C6G5
//nPos = fileAccessI.write (b,0,nRead); 4c"x&x|
} h`X>b/V
catch(Exception e){e.printStackTrace ();} vMBF7Jfx
} ?2D1gjr
} D@:w/W
C(( 7
+k=BD s
//打印回应的头信息 W-9?|ei
public void logResponseHead(HttpURLConnection con) !KiN} p
{ _&0_@
for(int i=1;;i++) i|zs Li/
{ %au2kG,
String header=con.getHeaderFieldKey(i); Uj5%06
if(header!=null) .GG6wL<$?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )m .KV5K!
Utility.log(header+" : "+con.getHeaderField(header)); Rlvb@aXgy
else g8<Ja(J
break; 2, bo
} :CH?,x^!@
} 5&}~W)"9
iwJeV J
^{L/) Xy5
public void splitterStop() :Osw4u]JXd
{ EyJWi<
bStop = true; FbxrBM
} 3f;W+^NY
Jb. V4
:G+8%pUX]
} fJ \bm
$]eU'!2)
^HpUbZpat)
/* q/I':a[1
**FileAccess.java 3C8cvi[IS
*//文件访问(定位，写) X%iiz
package NetFox; Oj6PmUK4
import java.io.*; G[34:J
{FV_APL9_
oqu; D'8
public class FileAccessI implements Serializable{ )n8(U%q$
//9M~qHa"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kNW}0CDgs
RandomAccessFile oSavedFile; U Ke!zI
long nPos; /yRP>CX~
_T,X z_
1Yj^N"=
public FileAccessI() throws IOException +&t`"lRl&
{ Jzqv6A3G
this("",0); *AEN
} QFn .<@
R$vo
p#['CqP8
public FileAccessI(String sName,long nPos) throws IOException F(jvdq
{ :el]IH
oSavedFile = new RandomAccessFile(sName,"rw"); {*EA5;
this.nPos = nPos; # tN#_<W
oSavedFile.seek(nPos); Q>`|{m
} 8t{-
@.JhL[f
@EPO\\C"f
public synchronized int write(byte[] b,int nStart,int nLen) P)VysYb?
{ %!_okf
int n = -1; IhIPy~Hgt
try{ KW&5&~)2
oSavedFile.write(b,nStart,nLen); y[ikpp#ozY
n = nLen; zq(R!a6
} Q&p'\6~
catch(IOException e) Aw]W-fx
{ r!DUsE
e.printStackTrace (); $JH_
} #0yU K5J
K0681_bp
K,pQ11J
return n; Tnw0S8M
} V\C$/8v
Y!M&8;>
e!+_U C
} HzdtR
#;l~Y}7'
=&kd|o/i
/* *|Cmm>z"7
**SiteInfoBean.java :?LUv:G
*/ _FG?zE
package NetFox; ^Q)&lxlxpx
&y164xn'h
s\7]"3:wD
public class SiteInfoBean { UOi[#L@N
{+n0t1
l!6^xMhYk
private String sSiteURL; //Site's URL uif1)y`Q$C
private String sFilePath; //Saved File's Path =!@5!
private String sFileName; //Saved File's Name gO{XD.s
private int nSplitter; //Count of Splited Downloading File Re`'dde=
hj~nLgpN
I-=H;6w7
public SiteInfoBean() jrOqspv
{//nSplitter的缺省值为5 *)+K+J
//default value of nSplitter is 5 /hx|KC&:e
this("","","",5); '?WKKYD7N
} #!a}ZhIt
fu}ZOPu
VeLuL:4I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6jdNQC$#B
{ =Zg%& J
sSiteURL= sURL; ;@I4[4ph}
sFilePath = sPath; ^xB=d S~
sFileName = sName; Gw\-e;,
this.nSplitter = nSpiltter; 3&'u7e
STfcx]L
_{d0Nm
} r`t|}m
@qszwQav$
TB!z:n
public String getSSiteURL() _[eAA4h
{ ;r**`O
return sSiteURL; L=Pz0
} 3,x|w
3,Dc}$t
o.)8A8
public void setSSiteURL(String value) s>A!Egmo
{ ;QRnZqSv
sSiteURL = value; SHc<`M'+
} #osP"~{
%Ls5:Z=
%xa.{`}`U
public String getSFilePath() GI]sE]tZ
{ XOk0_[
return sFilePath; x/Nh9hh"
} ]HpKDb0+
\(S69@f
-#9Hb.Q;
public void setSFilePath(String value) }"V$li
{ &}YJ"o[I
sFilePath = value; Py&DnG'H
} 'G6M:IXno
@|N'V"*MT
#u<^
public String getSFileName() ;w\7p a
{ UUE:>[,
return sFileName; c^4^z"Mo`
} ,wyfMOGLt
X {["4
Y,?!"
public void setSFileName(String value) CG`s@5y>5
{ __F?iRrCM
sFileName = value; G`a,(<kT;
} 9;fyC=
C4Tn
p "J^
public int getNSplitter() T7wy{;
{ Lc0U-!{G
return nSplitter; [<2#C#P:6
} BdK2I!mm
xK8n~.T('
n$jOk |W
public void setNSplitter(int nCount) MS_@ Xe
{ E[z8;A^:0
nSplitter = nCount; B4/0t:^I
} ?iX1;c9
} AGH7z
tHvc*D
HQpw2bdy
/* u:6PAVW?
**Utility.java li U=&wM>
*/ 5|4=uoA<
package NetFox; stb)Tl^
Ql%0%naq1
h{$mL#J
public class Utility { Vy+%sG q"
4 ^=qc99
X2Z E9b
public Utility() yq?7!X
{ R%(ww
C4#EN}
JTK0#+?
} rO_|_nV[
fs43\m4=m
//线程睡眠 j-?zB.jAh
public static void sleep(int nSecond) %XpYiW#AK
{ %(9BWO
try{ wFgL\[$^|
Thread.sleep(nSecond); SP&Y|I$:
} wR x5` @
catch(Exception e) 3?}W0dZ$d
{ X5(S+;v"^
e.printStackTrace (); ^/)!)=?
} l7.W2mg
} Eyv|~D
&TpzJcd"
//日志 34@f(^d+^
public static void log(String sMsg) bZ/4O*B
{ Cb{n4xKW6
System.err.println(sMsg); fnZaIV=H
} \:ELO[(#|{
'CrBxaA]s
&$'=SL(Z
public static void log(int sMsg) LC!ZeW35
{ |o:[*2-
System.err.println(sMsg); .^?^QH3
} #rE#lHo
} DeMF<)#
HjX!a29Wf
*\UxdL 22
/* [lSQ?
**TestMethod.java Uf:G,%OYi
*/ V4('}Q!
package NetFox; + lha=
Bn[5M[
F(-1m A&-
public class TestMethod { ?q68{!{bi
U?MKZL7
208dr*6U
public TestMethod() oic}Go
{ ///xx/weblogic60b2_win.exe m4U7{sE
try{ G)I lkA@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,O9rL :?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AYC22(
SiteFileFetch fileFetch = new SiteFileFetch(bean); q=o"] 6
fileFetch.start(); OT&mNE4
} X(b"b:j'
catch(Exception e){e.printStackTrace ();} E!a5-SrR
tRqg')y
2n9E:tc
} <lx~/3<m
[M^ur%H
UE3#(:xA
public static void main(String[] args) Dn[iA~
{ F-^#EkEGe
new TestMethod(); b&Dc DX
} jY]hMQ/H
} uq}>5
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