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)); G"U^]$(+K
} 4S*dNYc
for(int i=0;i<nEndPos.length-1;i++) *rmM2{6
{ Hu"TEhW(2
nEndPos = nStartPos[i+1]; !Aw.)<teW
} c"pu"t@/Z
nEndPos[nEndPos.length-1] = nFileLength; 3ZhuC".c
} bdHHOpXM
} |9]_<X[ic
WNF#eM?[a
Zn6u6<O=
//启动子线程 4E@_Fn_#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lMe+.P|
for(int i=0;i<nStartPos.length;i++) =gHUY&sPu8
{ ;Mz7emt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z7R2viR[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N;* wd<
nStartPos,nEndPos,i); ,OBJ>_5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5?|yYQM0tK
fileSplitterFetch.start(); ilwIqj
} =$uSa7t#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c1Hp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T}K@ykT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", iIc/%< ;
nEndPos = " + nFileLength); j{Sbf04
// fileSplitterFetch[nPos.length-1].start(); #1Iev7w
:Q"p!,X=-
Wx|De7*
//等待子线程结束 Uac.8wQh
//int count = 0; 1'b}Y8YO
//是否结束while循环 jQdIeQD+
boolean breakWhile = false; ~;0W +
w6|l ~.$=
r+,JM L
while(!bStop) 'LC0hoV
{ !nTI(--
write_nPos(); K,dEa<p
Utility.sleep(500); mLDuizWI
breakWhile = true; G|qsJ
K/z2.Npn
[vOk=
for(int i=0;i<nStartPos.length;i++) $.3J1DU
{ DUb8 HgcV}
if(!fileSplitterFetch.bDownOver) A5RM&y
{ smHQ'4x9
breakWhile = false; HEm XB=
break; lA n^)EL
} -lb%X3`
} c=33O,_
if(breakWhile) [FeN(8hGS
break; Xr{ r&Rl
o':K4r;
hI,+J>
//count++; E6#")2C~
//if(count>4) 34 I Cn~
// siteStop(); U_~r0
} zA8Tp8(
E=t^I/f)E
fr8hT(,s)
System.err.println("文件下载结束！"); zin'&G>l
} .cB>ab&
catch(Exception e){e.printStackTrace ();} spma\,o
} Pa"[&{:
\omfWWpK
QG5)mIJ
//获得文件长度 [uFv_G{H
public long getFileSize() L[MAc](me-
{ jm,:jkr
int nFileLength = -1; 7x.] 9J
try{ -+kTw06_C
URL url = new URL(siteInfoBean.getSSiteURL()); [9\Mf4lh#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yXBWu=w3`O
httpConnection.setRequestProperty("User-Agent","NetFox"); N\85fPSMG|
6<No_x |_
sq+cF/jo6
int responseCode=httpConnection.getResponseCode(); 2D4c|R@+
if(responseCode>=400) Z._%T$8aJv
{ (VBO1f
processErrorCode(responseCode); :+%Yul
return -2; //-2 represent access is error DiSU\?N2'
} ~>rnq7j
nk2H^RM^
rvPmd%nk-
String sHeader; ]wEFm;N
@-XMox/
CW?R7A/
for(int i=1;;i++) LNM#\fb
{ 2bxW`.fa
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )V9wU1.
//Utility.log(in.readLine()); A4Tjfc,rx9
sHeader=httpConnection.getHeaderFieldKey(i); ?F9c6$|
if(sHeader!=null) oFp4*<\
{ b;"Z`/h
if(sHeader.equals("Content-Length")) TCK<IZKLqK
{ =qS\+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XT{ukEvDR
break; 1=mb2A
} !uAqY\Is
} ~Q+J1S]Fs
else $pj;CoPm
break; rM)#}eZK!
} bjql<x5d
} 4td9=dNA+l
catch(IOException e){e.printStackTrace ();} \{a 64
catch(Exception e){e.printStackTrace ();} @MfZP~T+
T:S[[#f{5
Qp~3DUM
Utility.log(nFileLength); isor%R!
E$s?)
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return nFileLength; 7?qRz
} K#[z5
8 G:f[\^
U\(T<WX,
//保存下载信息（文件指针位置） H+ 7Fw'u
private void write_nPos() YkI_i(
{ T49^
try{ 5]Y?NN,GR
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8GT4U5c ;
output.writeInt(nStartPos.length); E/3<8cV
for(int i=0;i<nStartPos.length;i++) #>O+!IH
{ AO]1`b:
// output.writeLong(nPos); tWITr
output.writeLong(fileSplitterFetch.nStartPos); ejlau#8"
output.writeLong(fileSplitterFetch.nEndPos); xQ>T.nP}1
} )m>Y[)8!
output.close(); IAb-O
} |J&=h|-A
catch(IOException e){e.printStackTrace ();} z;Dc#SZnO(
catch(Exception e){e.printStackTrace ();} ,`ju(ac!
} Q =4~uz|
b2UqN]{
58gkE94
//读取保存的下载信息（文件指针位置） (dAE
private void read_nPos() ]TSzT"_r~~
{ #oxP,LR
try{ oU)3du
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !_+ok$"d
int nCount = input.readInt(); k1Sr7|
nStartPos = new long[nCount]; I4MZJAYk
nEndPos = new long[nCount]; d%Nx/DS)
for(int i=0;i<nStartPos.length;i++) SfUbjs@a
{ 7 MG<!U
nStartPos = input.readLong(); f- ~]
nEndPos = input.readLong(); t^8|t(Lq
} /H :Bu
input.close(); ~A,(D-
} cb%ML1c
catch(IOException e){e.printStackTrace ();} c->?'h23)
catch(Exception e){e.printStackTrace ();} -\V;Gw8mD
} X oh@(%
?io,8
!c=EB`<*
private void processErrorCode(int nErrorCode) V5S6?V\
{ vze|*dKS
System.err.println("Error Code : " + nErrorCode); Y!3i3D
} *2r(!fJP=^
9[Xe|5?c
JwcC9 O
//停止文件下载 ]QmY`pTB`
public void siteStop() 'Ad|*~
{ PAs.T4Av^
bStop = true; '2v$xOh!y
for(int i=0;i<nStartPos.length;i++) hXQo>t-$
fileSplitterFetch.splitterStop(); \\$wg
!-s6B
mZ4I}_\,
} I0(nRu<
} e4Xo(EY &
//负责部分文件的抓取 G|)fZQ1nS
**FileSplitterFetch.java a\Dw*h?b~
*/ yI8 /m|
package NetFox; B}npom\tC
jn#Ok@tZ
A:,R.P>`C
import java.io.*; -ZBSkyMGy
import java.net.*; b~Oc:
QS2~}{v
H?)?(t7@
public class FileSplitterFetch extends Thread { +V/mV7FK
m'5rzZP
.*+e?-
String sURL; //File URL A3zO&4f ]
long nStartPos; //File Snippet Start Position $iOkn|~<@W
long nEndPos; //File Snippet End Position W0KSLxM
int nThreadID; //Thread's ID zq4)Uab*
boolean bDownOver = false; //Downing is over 5vjtF4}7!
boolean bStop = false; //Stop identical X1\ao[t<;c
FileAccessI fileAccessI = null; //File Access interface ZIvP?:=!
G,A;`:/
#{suH7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +@#k<.yqn
{ I=o/1:[-
this.sURL = sURL; ?\Lf=[
this.nStartPos = nStart; 5=9gH
this.nEndPos = nEnd; Dp" xO<PE2
nThreadID = id; =YeI,KbA)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (S k+nD
} MU5#ph
$Y_v X 2
6sl2vHzA
public void run() _33YgO
{ ?)'+l
while(nStartPos < nEndPos && !bStop) :H`Z.>K
{ DF~{i{
\[;Qqn0
/2AeJH\-
try{ g'{hp:
URL url = new URL(sURL); g)#.|d+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y#aHGZ$i
httpConnection.setRequestProperty("User-Agent","NetFox"); %!QY:[
String sProperty = "bytes="+nStartPos+"-"; zwpgf
httpConnection.setRequestProperty("RANGE",sProperty); +5IC-=ZB
Utility.log(sProperty); +q@g
zoI0oA
8f{;oO
InputStream input = httpConnection.getInputStream(); Aq"<#:
//logResponseHead(httpConnection); K18Sj,]B
%)@3V8OI
e x`mu E
byte[] b = new byte[1024]; o"./
int nRead; (DrDWD4_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DqTp*hI
{ @8xa"Dc
nStartPos += fileAccessI.write(b,0,nRead); VN!+r7w'
//if(nThreadID == 1) WnZn$N.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @F,8M
} &[iunJv:eq
sQ8_j
qGPIKu
Utility.log("Thread " + nThreadID + " is over!"); }iCcXZ&5^
bDownOver = true; >Lrud{
//nPos = fileAccessI.write (b,0,nRead); "=ogO/_Q"
} _|%l) KO
catch(Exception e){e.printStackTrace ();} 4c/.#?
} [j^c&}0
} S((\KL,
Zn9ecN
Fi!XaO
//打印回应的头信息 $2+(|VG4F
public void logResponseHead(HttpURLConnection con) ra*(.<&
{ Msea kF
for(int i=1;;i++) YoEL|r|
{ <.qhW^>X
String header=con.getHeaderFieldKey(i); /i
if(header!=null) -32?]LN}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fPLi8`r
Utility.log(header+" : "+con.getHeaderField(header)); v<wR`7xG
else AD/7k3:
break; 9?~K"+-SI
} a="\?L5
} DeTD.)pS
Kc[Y .CH
wX!>&Gc.
public void splitterStop() iAAlld1
{ ]fgYO+
bStop = true; Oe^oigcM
} auKGm:
:n t\uwh
IFg(Ze~
} 0`L>t
`aw5"ns^V
OY>0qj
/* t/HUG#W{
**FileAccess.java NtnKS@Ht
*//文件访问(定位，写) Hlg Q0qb
package NetFox; eGJ}';O,g
import java.io.*; ^.f`6 6/
MJ+]\(
"uthFE
public class FileAccessI implements Serializable{ R#QcQx
4xE [S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EFYyr f@
RandomAccessFile oSavedFile; 4Nx]*\\
long nPos; iA[WDB\|0
gqi|k6V/
itg PG
public FileAccessI() throws IOException <&$:$_ah
{ HSR^R
this("",0); c!{]Z_d\
} lVmm`q6n9
{hLS,Me
JTxHM?/G
public FileAccessI(String sName,long nPos) throws IOException wv eej@zs
{ %HNe"7gk
oSavedFile = new RandomAccessFile(sName,"rw"); ?z2k74&M^
this.nPos = nPos; 8@f=GJf
oSavedFile.seek(nPos); 0y"Ra%Y
} pM^r8kIH
EZ.|6oug\
#)r
public synchronized int write(byte[] b,int nStart,int nLen) NzP5s&,C69
{ Ak\w)!?s
int n = -1; '{t&!M`
try{ $ 4& )
oSavedFile.write(b,nStart,nLen); ^j1WF[GiSO
n = nLen; 6IVa(;
} ^nS'3g^"
catch(IOException e) jo-qP4w
{ ;DkX"X+
e.printStackTrace (); >$.lM~k
} <~[A
z}" Xt=G?
^@&RJa-kb
return n; km]RrjRp
} ^_cR
v/4Bt2J
W+'|zhn
} #_, l7q8U
w<3g1n7R
j^g^=uau
/* ~;f,Ad`Q
**SiteInfoBean.java ;34 m!\N5
*/ *:q,G
package NetFox; l~/g^lN
qx1}e
azj:Hru&t#
public class SiteInfoBean { o+H;ZGT5H
(>OCLmV$
~olta\|
private String sSiteURL; //Site's URL ,~!rn}MI<
private String sFilePath; //Saved File's Path r&G=}ZMO
private String sFileName; //Saved File's Name 2VNMz[W'
private int nSplitter; //Count of Splited Downloading File vsjl8L
Kh!h_
DL^}?Ve
public SiteInfoBean() `XwFH#_
{//nSplitter的缺省值为5 Hd1e9Q,:|
//default value of nSplitter is 5 Y6|8;2E
this("","","",5); u |hT1l
} USKa6<:{W
SWX;sM
7PDz ]i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m17H#!`
{ K%) K$/A
sSiteURL= sURL; 9tW=9<E
sFilePath = sPath; 1k5o?'3&
sFileName = sName; n$*'J9W~
this.nSplitter = nSpiltter; ?lh `>v
1!@KRV
-?A,N,nnX
} UIUCj8QJg
,cR=W|6cQm
\BT8-}
public String getSSiteURL() r@_`ob RW;
{ cO,ELu
return sSiteURL; ;:nO5VFOg
} !5rja-h
D8otUDB{
\:cr2w'c
public void setSSiteURL(String value) L:HJ:
{ Ou~|Q&f'
sSiteURL = value; MLV_I4o
} KGCm@oy
H7 acT
$a|DR
public String getSFilePath() $?^#G8J
{ :NL.#!>/
return sFilePath; FF:Y7wXW
} *R17 KMS
:T5p6:
0*66m:C2
public void setSFilePath(String value) @\,WJmW
{ -lM4*+f
sFilePath = value; P 0xInW F
} uf;^yQi
}(AgXvRq
-ec~~95
public String getSFileName() YYFJJ,7?
{ $O*rxQ}
return sFileName; wv>uT{g#
} bXoj/zek
D*d@<&Bl4<
FL5u68
public void setSFileName(String value) =/@c9QaVB
{ cyq]-B
sFileName = value; _5I" %E;S
} @`<vd@
FHVZ/ e
eR.ucTji
public int getNSplitter() g2b%.X4
{ wy5vn?T@
return nSplitter; *S.R#4w
} Gd$odKtI
AY['!&T
)>q.!"B
public void setNSplitter(int nCount) 3 }Z[d
{ a%>p"4WL
nSplitter = nCount; "WOY`su>
} *V(TNLIh;
} JF]HkH_u
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mc_`:I=
/* U@v=q9'W
**Utility.java p(UUH3%W
*/ p{7"a
package NetFox; n|F$qV_p\
}YHoWYR
gc@,lNmi
public class Utility { 9,y*kC
E!J;bX5
ou6|;*>d
public Utility() %7q,[g8
{ $aTZC>R
RO,
u= ( kii=/
} 9|O#+_=+v
N?0T3-/K
//线程睡眠 M H }4F
public static void sleep(int nSecond) ;bq_Y/"
{ s<x2*yVUA
try{ jJ86Ch
Thread.sleep(nSecond); O [GG<Um
} Dt\F]\6sd
catch(Exception e) 8E{<t}
{ nb0V~W
e.printStackTrace (); RP&H9>
} =if5$jE3
} X.V7od>
Y( n# =
//日志 3=V79&
public static void log(String sMsg) ~0r:Wcj x
{ aB~?Y+m
System.err.println(sMsg); e"P>b? OY
} !Y/$I?13Z
O7bTu<h=
::N'tcZ^2
public static void log(int sMsg) SUxz &xH
{ GQO}E@W6C
System.err.println(sMsg); h{I)^8,M
} lw0l86^Y
} Js[dT|>.
I:[^><?E
TG'_1m*$
/* -L(F:
**TestMethod.java WjtmV2b<7
*/ Jw?J(ig^
package NetFox; p7}xgUxX
z/aZD\[_
, }O>,AU
public class TestMethod { sI/Jhw)
Hzh?w!Ow
<[Ae0UK
public TestMethod() j-@3jFu
{ ///xx/weblogic60b2_win.exe _v:t$k#sN
try{ _oxhS!.*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4~=/CaG~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {Sm^F
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8C3oj
fileFetch.start(); pme5frM|
} E'zLgU)r`
catch(Exception e){e.printStackTrace ();} =b2/g[
~#+ Hhc(
.^0@^%Wi
} ;HRIB)wF
ys|a ^VnN
VJ;4~WgBz
public static void main(String[] args) dBkw.VOW
{ Q[J%
new TestMethod(); /9<zG}:B
} Ha{#
} Qvt
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