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)); @"87F{!
} *YV S|6bs
for(int i=0;i<nEndPos.length-1;i++) 4cgIEw[6
{ 0irr7Y
nEndPos = nStartPos[i+1]; ROAI9sW0
} 4*H"Z(HP
nEndPos[nEndPos.length-1] = nFileLength; >%%=0!,yX
} -$k>F#
} xF8S*,#,*
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_9If/RD
//启动子线程 j'rS&BIG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m2bDHQ+
for(int i=0;i<nStartPos.length;i++) ur%$aX)
{ y;`eDS'0.N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wz(K*FP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'imU`zeo
nStartPos,nEndPos,i); p]|LV)R n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *o?i:LE]
fileSplitterFetch.start(); Fz"ff4Bx [
} f05d ;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #gZ|T M/h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~9M!)\~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;IP~Tb]&
nEndPos = " + nFileLength); [~%`N*G
// fileSplitterFetch[nPos.length-1].start(); &w\I<J`T
yXfMzG
o#hI5
//等待子线程结束 KX+ey8@[
//int count = 0; C7"HQQ
//是否结束while循环 ?-~I<f]_
boolean breakWhile = false; DguB
SG]K
WStnzVe
while(!bStop) T 1Cs>#)
{ '1+.t$"/tU
write_nPos(); "Ai6<:ml
Utility.sleep(500); 1"E\C/c
breakWhile = true; 7>.OVh<
! q6hC
`lCuU~~ag
for(int i=0;i<nStartPos.length;i++) 4br6$
{ U6j/BJT"
if(!fileSplitterFetch.bDownOver) [#b2%G1
{ v<h;Di@
breakWhile = false; ;bjnL>eW
break; NB)t7/Us
} F?]N8W
} YMzBAf
if(breakWhile) Go8F5a@j
break; BQrL7y
F@SG((`
*@M3p}',M
//count++; /6tcSg)
//if(count>4) 3'#%c>_
// siteStop(); 8 njuDl
} aj7dH5SZl
L(o#4YH}>J
gA:TL{X0
System.err.println("文件下载结束！"); bx;f`8SN
} tbur$00
catch(Exception e){e.printStackTrace ();} {*xBm#
} VTw/_Hf2p
~ =.CTm]vf
$$gtZ{ukQ
//获得文件长度 0s%6n5>
public long getFileSize() SGf9U^ds
{ P;U@y"s
int nFileLength = -1; aqL<v94wX
try{ YKx 1NC
URL url = new URL(siteInfoBean.getSSiteURL()); Jt=>-Spj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g9V.13k
httpConnection.setRequestProperty("User-Agent","NetFox"); 5' \)`
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n<R \w''x
int responseCode=httpConnection.getResponseCode(); lX;mhJj!
if(responseCode>=400) eE3-t/=
{ /$`;r2LG
processErrorCode(responseCode); h}6_ybmZ
return -2; //-2 represent access is error +TX/g~
} "iek,Y}j7
>>V&yJ_
> V%Q O>C
String sHeader; h6QWH
<94WZ?{p
|5ONFde"0
for(int i=1;;i++) dU+0dZdKO
{ &o.iUk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); otq,R6 ^
//Utility.log(in.readLine()); g!^J,e=
sHeader=httpConnection.getHeaderFieldKey(i); In(NF#
if(sHeader!=null) el*9 Ih
{ ~3 @*7B5Q
if(sHeader.equals("Content-Length")) Czu1)y
{ *8-p7,D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); otnV-7)@
break; a<p %hY3
} +Jq`$+%C
} !;WbOnLP
else 1n3$V:00
break; ~e^)q>Lb7(
} <%?uYCD
} Bbs 0v6&,
catch(IOException e){e.printStackTrace ();} !R{em48D
catch(Exception e){e.printStackTrace ();} r$DZkMue
aL)$b
x5vzPh`
Utility.log(nFileLength); A2_Ls;]
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,%8$D-4#_
return nFileLength; x]'H jTqX
} %!wq:~B1
&;U|7l~vl
.zwVCW,u
//保存下载信息（文件指针位置） K+> V|zKuk
private void write_nPos() a7 )@BzF#
{ R0IF'
try{ M,G8*HI"
output = new DataOutputStream(new FileOutputStream(tmpFile)); T{HfP
output.writeInt(nStartPos.length); Oga1u
for(int i=0;i<nStartPos.length;i++) G5umeqYC
{ n)CH^WHL&
// output.writeLong(nPos); RpeBm#E2
output.writeLong(fileSplitterFetch.nStartPos); 'FxYMSZS$
output.writeLong(fileSplitterFetch.nEndPos); BvJ\x)
} I}%mfojC
output.close(); }K;iJ~kD1
} L8Dm9}
catch(IOException e){e.printStackTrace ();} 3N3*`?5c<
catch(Exception e){e.printStackTrace ();} kA,4$2_o
} zKMv7;s?
l#ygb|=x
!PI0oh
//读取保存的下载信息（文件指针位置） !qS05
private void read_nPos() Cz[5Ug'V
{ ~Jxlj(" 0(
try{ B3.X}ys#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2%]t3\XW
int nCount = input.readInt(); Xv&%2-V;
nStartPos = new long[nCount]; Gl"wEL*
nEndPos = new long[nCount]; QpJIDM/
for(int i=0;i<nStartPos.length;i++) #:I^&~:
{ !p"Kd ~
nStartPos = input.readLong(); (xQI($Wq*M
nEndPos = input.readLong(); 2{gwY85:
} 2D_6
input.close(); ++gPv}:$X
} ZR2\dH*
catch(IOException e){e.printStackTrace ();} -G!6U2*#
catch(Exception e){e.printStackTrace ();} `|JI\&z
} I*9Gb$]=
K"I{\/x@
D/*vj|
private void processErrorCode(int nErrorCode) (I!1sE!?1
{ s)Gb!-``
System.err.println("Error Code : " + nErrorCode); 'N|2vbi<
} C?(y2p`d\
w4aiI2KFq
qs "s/$
//停止文件下载 6T]Q.\5BZ
public void siteStop() ~Ji>[#W K
{ WQTendS
bStop = true; 63SVIc~wT
for(int i=0;i<nStartPos.length;i++) L*IU0Jy>
fileSplitterFetch.splitterStop(); +Bn?-{h=
KG-UW
k=FcPF"
} pBvo M={2!
} sq48#5Tc^r
//负责部分文件的抓取 ~{9x6<g!
**FileSplitterFetch.java '%:5axg?]
*/ R rxRa[{Z
package NetFox; ^|r`"gOJ3
zQ=aey%
[(!Q-8
import java.io.*; Zr5'TZ`$
import java.net.*; z3ZuC{
L2k;f]
Y'?Iznb
public class FileSplitterFetch extends Thread { Y0rf9
fo*!a$)
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String sURL; //File URL 5#P: "U
long nStartPos; //File Snippet Start Position 2"zIR(
long nEndPos; //File Snippet End Position ^?#@[4?"
int nThreadID; //Thread's ID ]y$)%J^T
boolean bDownOver = false; //Downing is over [;Vi~$p|Eo
boolean bStop = false; //Stop identical rT o%=0P
FileAccessI fileAccessI = null; //File Access interface 1XQ87~
E8+8{ #f;
vsjM3=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gp%tMTI1
{ Q4#\{" N!
this.sURL = sURL; |%n|[LP'
this.nStartPos = nStart; 3SmqXPOw
this.nEndPos = nEnd; sek6+#|=
nThreadID = id; h!ZZ2[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ER/\ +Z#Z
} d"z*Nb
B6-AIPb
gq=0L:
public void run() Ni&,g
{ Dy98[cL
while(nStartPos < nEndPos && !bStop) \]Kq(k[p
{ }'%$7vL`Ft
UnJi& ~O
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try{ //VG1@vaVX
URL url = new URL(sURL); #@IQlqJfY7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n(9F:N
httpConnection.setRequestProperty("User-Agent","NetFox"); _P>1`IR
String sProperty = "bytes="+nStartPos+"-"; l)|z2H
httpConnection.setRequestProperty("RANGE",sProperty); $hC~af6
Utility.log(sProperty); W=q?tD~V
7l[t9ON
4U_rB9K$
InputStream input = httpConnection.getInputStream(); o-~-F+mj#
//logResponseHead(httpConnection); }ZxW"5oq
jc3ExOH
|L*6x S[
byte[] b = new byte[1024]; rD_Ss.\^g
int nRead; 7$;c6_se
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JiG8jB7%}
{ =B1`R%t
nStartPos += fileAccessI.write(b,0,nRead); T@2f&Un^
//if(nThreadID == 1) /M5=tW#e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "#[o?_GaJ
} h]G6~TYI5
3 t~X:
avF&F
Utility.log("Thread " + nThreadID + " is over!"); xKRfl1
bDownOver = true; ZKVp[A
//nPos = fileAccessI.write (b,0,nRead); [I#Q
} b=6ZdN1
catch(Exception e){e.printStackTrace ();} fJ,8g/f8
} *C,$W\6sz
} 1Al=v
:DF`A(
;Of?fe5:
//打印回应的头信息 Q&\ZC?y4
public void logResponseHead(HttpURLConnection con) Tom}sFl][
{ GA({ri
for(int i=1;;i++) 0b!fWS?,k0
{ \Qe'?LRu{
String header=con.getHeaderFieldKey(i); x'VeL|
if(header!=null) r%OrH-T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cj,&&3sbV
Utility.log(header+" : "+con.getHeaderField(header)); K*hf(w9="%
else XyN`BDFi
break; _p3WE9T
} cx,u2~43A&
} ,i1fv "
%a%+!wX0x
M}_M_
public void splitterStop() C={sE*&dYX
{ ^v()iF !
bStop = true; \J#I}-a&j
} ^/4{\3
dA3`b*nC
/jn:e"0~
} J-HabHv
G5C#i7cpm
oW` *FD
/* B)LXxdkOn
**FileAccess.java #RsIxpc
*//文件访问(定位，写) PDa06(t7
package NetFox; @5uyUSt]
import java.io.*; 7]0\[9DyJ
"'LOaf$X
~}FLn9@*
public class FileAccessI implements Serializable{ lUm}nsp=X
lW@:q04Z$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #==[RNM%ap
RandomAccessFile oSavedFile; JJ= ~o@|c
long nPos; 7ipY*DT8
5wVi{P5+
dvH67 x
public FileAccessI() throws IOException {ILQ CvP*
{ aG8;,H=%,
this("",0); cfF-e93T
} o F,R@f
|$i1]Dr6
dRarNW
public FileAccessI(String sName,long nPos) throws IOException `\}zm~
{ zjhR9
oSavedFile = new RandomAccessFile(sName,"rw"); 8I|1Pl
this.nPos = nPos; ]MBJ"1F
oSavedFile.seek(nPos); TO8\4p*tE
} P7^TRrMF
iz$v8;w
~=aI2(b
public synchronized int write(byte[] b,int nStart,int nLen) s;=J'x)~%
{ G=0}IPfp
int n = -1; nY.Umj
try{ pNk,jeo
oSavedFile.write(b,nStart,nLen); ^U|CNB%.
n = nLen; ^Ypb"Wx8
} |Cxip&e>
catch(IOException e) +=lcN~U2
{ Y=#mx3.
e.printStackTrace (); L>K39z~,
} n$Oky-P"
d%"@#bB
{yl/T:Bh&
return n; `~s,W.Eu4
} =Am*$wGI
7xa@wa?!L
>H]|A<9u(
} g#bfY=C
5<>R dLo
b&_u O
/* jmwQc&
**SiteInfoBean.java .>\>F{#~
*/ 0V>N#P]
package NetFox; T3PaG\5B
/m|&nl8"qe
[sh"?
public class SiteInfoBean { znDtM1sLeV
-n$rKEC4
y*TNJJ|
private String sSiteURL; //Site's URL .$T:n[@
private String sFilePath; //Saved File's Path Yk*57&QI
private String sFileName; //Saved File's Name 0OoO cc
private int nSplitter; //Count of Splited Downloading File DG%%]
=Z$=-\<x0.
kA9 X!)2w
public SiteInfoBean() \Q BpgMi(
{//nSplitter的缺省值为5 g{f>jd
//default value of nSplitter is 5 [OToz~=)
this("","","",5); HZ`G)1&)
} qS`|=5f
F(kRAe;
26klW:2*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "vHAp55B{
{ W YqL
sSiteURL= sURL; M`,Z#)Af
sFilePath = sPath; 3Tte8]0
sFileName = sName; #p:jKAc3
this.nSplitter = nSpiltter; 1Z{p[\k
%emPSBf@
4m~stDlN
} bT6)(lm
)*AA9
x;b+gIz*
public String getSSiteURL() f4;8?
{ 7XI4=O};&%
return sSiteURL; 5@r Zm4U
} fbbl92p
EG:WE^4
| 3/p8
public void setSSiteURL(String value) Bv|9{:1%X}
{ !-}*jm p<
sSiteURL = value; UK9MWC5g9
} o[+|n[aT)3
V5^b6$R@
:FgRe,D
public String getSFilePath() ,0u0 '
{ R~?;KJ
return sFilePath; vrEaNT$J-
} oL/^[TXjH
XjM)/-w
X;a{JjN
public void setSFilePath(String value) A2FU}Ym0=
{ uEO2,1+
sFilePath = value; 2n r UE
} H_r'q9@<>
ZN]c>w[ )I
4 ~|TKd{
public String getSFileName() .6A:t?.
{ Pj5#G0i%
return sFileName; w0`L)f5v
} Pw0KQUs
hb\Y)HSp/
(dprY1noC
public void setSFileName(String value) ;77o%J'l
{ .BB:7+
sFileName = value; :[rKSA]@
} #$^i x
8`?j*FV7kq
&1C9K>
public int getNSplitter() 7CN[Z9Y^}
{ ZUI\0qh+
return nSplitter; QKkr~?sTO
} p?NjxQLA
L/+J|_J)
,^Srd20
public void setNSplitter(int nCount) J7] 60H#P
{ s7.*o@G
nSplitter = nCount; ; SM^
} 13az[
} YD.^\E4o
:|mkI#P.
:pu{3-n.
/* 4gNRln-
**Utility.java tLXw&hFk`g
*/ 4'=N{.TtO
package NetFox; \uPTk)oaB
>o=p5#{
EQhV}9
public class Utility { #C7j|9Ew1]
3^UsyZS)
P&^7wud-sb
public Utility() e[dRHl
{ aM}"DY-_ h
F|K4zhK
A)\DPLAG
} `5&V}"lB
[1MEA;
//线程睡眠 ! HC<aWb
public static void sleep(int nSecond) Y-{BY5E.
{ Czxrn2p/
try{ cY]Y8T)
Thread.sleep(nSecond); q,&T$Tw
} Y--8v#t
catch(Exception e) kw}1CXD
{ 4^^rOi0
e.printStackTrace (); jch8d(`?d
} eV%bJkt.
} Y6PA\7Y\
xJGeIh5
//日志 s@iCfXU
public static void log(String sMsg) nv{4 U}&P
{ k|C8sSH
System.err.println(sMsg); 5z>\'a1U
} R u-rp^a
jdf@lb=5l
y]%,Y=%X
public static void log(int sMsg) cN>i3}fq
{ =Q/>g6
System.err.println(sMsg); I*2rS_i[T
} #L$ I%L"
} xB+H7Ya
[wG%@0\
ljON_*
/* hyoZh Y
**TestMethod.java =lD]sk
*/ 34:EpZO@
package NetFox; 0M98y!A 5^
a $%[!vF
loe>"_`Cq
public class TestMethod { lM"7 Z
c`; LF'!
d~8~RT2m
public TestMethod() RZ%X1$
{ ///xx/weblogic60b2_win.exe A$6b=2hc>
try{ PlUjjJU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mkA|gM[g7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7#3)&"j
SiteFileFetch fileFetch = new SiteFileFetch(bean); D:EF@il
fileFetch.start(); V~Lq,oth
} sR.j~R
catch(Exception e){e.printStackTrace ();} Uroj%xN
aB'@8[]z
(=/;rJ`q
} MT0{hsuK9
R*m"'|U
= h( n+y<
public static void main(String[] args) Ti'kn{ Zv
{ Y sV
new TestMethod(); D.`\ ^a
} <DS6-y
} N2e<Y_T
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