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)); #_x5-?3
} "wcw`TsK
for(int i=0;i<nEndPos.length-1;i++) ]b]J)dDI
{ +}1zw<
nEndPos = nStartPos[i+1]; TDbSK&w :s
} Z9NND
nEndPos[nEndPos.length-1] = nFileLength; \2=I//YF
} b{,v?7^4
} 63%V_B|
[B`4I
u{va2n/
//启动子线程 nSh~mP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yH]Q;X'
for(int i=0;i<nStartPos.length;i++) XkkzY5rxOc
{ SPRTJdaC9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AX%}ip[PC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h,B4Tg'
nStartPos,nEndPos,i); &zB>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S[q:b .
fileSplitterFetch.start(); @k)J i!7
} YmFg#eS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @[?ZwzY:9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aem gGw<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n*ShYsc
nEndPos = " + nFileLength); 2L;=wP2?{
// fileSplitterFetch[nPos.length-1].start(); 'I+M*Iy
nA_'jl
^'`(E_2u
//等待子线程结束 QEbf]U=
//int count = 0; .)+c01
//是否结束while循环 %qo.n v
boolean breakWhile = false; *xpn-hCp<
HfhI9f_x
yA"?Hv\o;
while(!bStop) IO9|o!&>
{ h%$^s0w
write_nPos(); GTTEg{
Utility.sleep(500); !~%DR~^`
breakWhile = true; EVZ1Z
j!!s>7IZ
k7rg:P
for(int i=0;i<nStartPos.length;i++) xR%NiYNQz
{ QtG6v<A
if(!fileSplitterFetch.bDownOver) M&hNkJK*G
{ 60{DR >S
breakWhile = false; D8u`6/^
break; N9#xTX
} 'Ca;gi !U
} &dWGa+e
if(breakWhile) F1_,V?
break; N0^SWA|S
*A8*FX>\F
,D }Ka?
//count++; b(R.&X
//if(count>4) i~v[3e9y7
// siteStop(); WHv6E!^\_
} |hi,]D^Kc
R\&z3<-S
M[z1B!rT
System.err.println("文件下载结束！"); 56c[$ q
} oVZzvK(zR
catch(Exception e){e.printStackTrace ();} }PBL
} !idVF!xG
4XVwi<)
|4pl}:g/Z
//获得文件长度 PPySOkmS3
public long getFileSize() >0ZG&W9
{ GXD<X_[
int nFileLength = -1; 9)S3{i6w
try{ $MQ<QP
URL url = new URL(siteInfoBean.getSSiteURL()); ~/JS_>e#6P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nIlTzrf6
httpConnection.setRequestProperty("User-Agent","NetFox"); TW(X#T@Z6I
ic!% }S?
r_Ou\|jU
int responseCode=httpConnection.getResponseCode(); y>E:]#F
if(responseCode>=400) Vq-Kl[-|
{ wN%lc3[/z2
processErrorCode(responseCode); fB7Jx6
return -2; //-2 represent access is error 2BF455e
} -eh .Tk
+L'Cbv="
\*{MgwF
String sHeader; <N~9=g3
+UX~'t_'v
&0bq3JGW
for(int i=1;;i++) (=WYi~2v
{ 3ww\Z8UeK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |1A0YjOD
//Utility.log(in.readLine()); |X XO0
sHeader=httpConnection.getHeaderFieldKey(i); SYsO>`/ )
if(sHeader!=null) L'KKU4zj
{ p&<n_b
if(sHeader.equals("Content-Length")) oO3^9?Z
{ t$t'{*t( T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I;wxgWOP
break; u$5.GmKm
} n=~!x
} [!3cWJCt
else ?Q"<AL>Z
break; y1}2hT0,
} @f|~$$k=
} <Dgf'GrJ
catch(IOException e){e.printStackTrace ();} VCnf`wZB"
catch(Exception e){e.printStackTrace ();} ^["D>@yIR
)[UYCx'
9SA%'
Utility.log(nFileLength); `DSFaBj,
Ce}m$k
f9Xa}*
return nFileLength; ZRw^< +
} ft@#[Bkx
$'d,X@}8
_D{FQRU<YD
//保存下载信息（文件指针位置） Dt7z<1-)l
private void write_nPos() xfX|AC
{ @C[p?ak
try{ >b0Bvx-
output = new DataOutputStream(new FileOutputStream(tmpFile)); vNdX
output.writeInt(nStartPos.length); Syl9j]
for(int i=0;i<nStartPos.length;i++) <Tbl|9
{ !h}Vz
// output.writeLong(nPos); 0d:t=LKw)
output.writeLong(fileSplitterFetch.nStartPos); ! ,H6.IH;S
output.writeLong(fileSplitterFetch.nEndPos); #fx"tx6
} ]Y->EME:W
output.close(); C-,#t5eir
} XJl 3\*
catch(IOException e){e.printStackTrace ();} qJl DQc-
catch(Exception e){e.printStackTrace ();} Mkt_pr
} #a|r ^%D
]0(ZlpT
fo>_*6i74
//读取保存的下载信息（文件指针位置） fh1-]$z`~
private void read_nPos() `RURC"
{ 9X#]Lg?b
try{ ,.=7{y~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l`X?C~JhJ
int nCount = input.readInt(); wXdt\@Qr
nStartPos = new long[nCount]; *h5L1Eq
nEndPos = new long[nCount]; `W1TqA
for(int i=0;i<nStartPos.length;i++) Ho&f[T(
{ z([HGq5
nStartPos = input.readLong(); `@6y Wb:X
nEndPos = input.readLong(); ZN'B@E=p
} D^];6\=.i
input.close(); *U8,Q]gS
} T|(w-)mv
catch(IOException e){e.printStackTrace ();} 4@ny%_/
catch(Exception e){e.printStackTrace ();} [V;u7Z\r-
} mmNn,>AO!
hS%oQ)zvE
dIQ3snG
private void processErrorCode(int nErrorCode) Z%I 'sWOd
{ aqi]5,
System.err.println("Error Code : " + nErrorCode); &f)pU>Di
} L0%W;m
?AI`,*^
)7E7K%:b,
//停止文件下载 *J4\KU
public void siteStop() :V)=/mR
{ c,G[Rk
bStop = true; )U}`x }:,
for(int i=0;i<nStartPos.length;i++) RO'b)J:j9
fileSplitterFetch.splitterStop(); SU~ljAF4
Wh%@
)g U#[}6H
} \x8'K
} zx?|5=+!
//负责部分文件的抓取 uCWBM
**FileSplitterFetch.java /}d)g4\j
*/ ,x[~|J!
package NetFox; 2ryg3%+O
NZXCaciG
rPifiLl A>
import java.io.*; JY D\VaW
import java.net.*; 2aUE<@RU[
)@.0ai
+KP&D.wIo
public class FileSplitterFetch extends Thread { y]ya.YG
3X`N~_+
-e+im(2D=
String sURL; //File URL ]^QO^{Sz
long nStartPos; //File Snippet Start Position IfCa6g<&(
long nEndPos; //File Snippet End Position \LM{.gzT
int nThreadID; //Thread's ID 4(8BWP~.y2
boolean bDownOver = false; //Downing is over S^5Qhv
boolean bStop = false; //Stop identical d}^hZ8k|
FileAccessI fileAccessI = null; //File Access interface z&.F YGq}
_=I&zUF
_U~~[I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YE-}1&8
{ )u=a+T
this.sURL = sURL; mr XmM<
this.nStartPos = nStart; 0T:U(5Y9
this.nEndPos = nEnd; W3B:)<f
nThreadID = id; &?APY9\.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,Q+.kAh !G
} 90a!_8o
:-T[)Q+-3
G=KXA'R)1.
public void run() uNvdlY]
{ 6{[uCxxl
while(nStartPos < nEndPos && !bStop) p!`S]\XEB
{ OT3~5j1[
lnrs4s Km
}Y3*X:i7
try{ j<d,7
URL url = new URL(sURL); Ce@"+k+w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xL!@$;J
httpConnection.setRequestProperty("User-Agent","NetFox"); VVi3g
String sProperty = "bytes="+nStartPos+"-"; ])Z p|?Y
httpConnection.setRequestProperty("RANGE",sProperty); M4L<u,\1s
Utility.log(sProperty); V6^=[s R
G~zP&9N|
cnU()pd
InputStream input = httpConnection.getInputStream(); X[1w(dU[
//logResponseHead(httpConnection); 7vB6IF
-b'/}zz
d+IN-lR(
byte[] b = new byte[1024]; ?p &Xf>K
int nRead; 2;ac&j1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mS &^xWPV
{ cbv%1DT3
nStartPos += fileAccessI.write(b,0,nRead); E-HK=D&W/
//if(nThreadID == 1) 3q0S}<h al
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X->` ~-aj
} L=kETJ:g
gq&jNj7V
Jr,**,wA
Utility.log("Thread " + nThreadID + " is over!"); VI8/@A1Gv
bDownOver = true; !+3nlG4cw
//nPos = fileAccessI.write (b,0,nRead); 7Q #A
} ?2Sm f
catch(Exception e){e.printStackTrace ();} O`0\f8/.?
} Md>9Daa~
} Ew&|!d
y6gaoj
m/ngPeZ
//打印回应的头信息 He LW*
public void logResponseHead(HttpURLConnection con) Lv:;}
{ V_jGL<X|
for(int i=1;;i++) 7$Pf
{ GT-ONwVDq
String header=con.getHeaderFieldKey(i); ~f?brQ?
if(header!=null) ~R~MC(5N[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $qM&iI-l0
Utility.log(header+" : "+con.getHeaderField(header)); :VlMszy}B3
else `/o|1vv@_
break; L#`X;:
} !>6`+$=U
} @{@)gE
M~g@y$
N'I9J?e Q
public void splitterStop() fs8C ^Ik>~
{ LN=#&7=$c
bStop = true; sJm v{wM
} HK`r9frn
){4$oXQ
c"NGE
} 5)p!}hWs
]NY^0SqM
L:Me
/* r9~IR
**FileAccess.java UDHMNubB
*//文件访问(定位，写) 0D}k ^W
package NetFox; g\@zQ^O?
import java.io.*; cEEnR1
2\G[U#~bi
5[H1nC @C
public class FileAccessI implements Serializable{ {hx=6"@
eyG[1EEU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7h\U}!
RandomAccessFile oSavedFile; 0B(Y{*QB
long nPos; [V41 Gk
vJuL+'[i
2z9N/SyN
public FileAccessI() throws IOException U6~79Hnt
{ TR!7@Mu3
this("",0); Enqs|fkbN
} {$v>3FG
g>_d,#F
gr4JaV
public FileAccessI(String sName,long nPos) throws IOException gHVD,Jr
{ /(Ryh6M
oSavedFile = new RandomAccessFile(sName,"rw"); )h/Qxf
this.nPos = nPos; 'UB"z{w%
oSavedFile.seek(nPos); 6o]>lQ}
} NzbHg p
)7a 4yTg!~
"Fqrk>Q~
public synchronized int write(byte[] b,int nStart,int nLen) PAv<J<d
{ 1f0maN
int n = -1; <Sp>uhet1
try{ qz|xow/ns@
oSavedFile.write(b,nStart,nLen); 49dN~k=
n = nLen; _cQhT
} T_~xDQ`v
catch(IOException e) =p#:v
{ t&rr;W]
e.printStackTrace (); `qa>6`\
} \,yg@R
r+}<]?aT>-
:A`jRe.
return n; x!A5j $k0
} $"`e^J9!!
1Ewg_/R
pcPRkYT[M
} 9,0}}3J
'z">4{5
N#7_)S[@0l
/* KL8WT6!RZ
**SiteInfoBean.java 'jBtBFzP-
*/ p&3~n: Fo
package NetFox; 5z9'~Gfb
_OR[RGy
"nC=.5/$
public class SiteInfoBean { r8[Ywn<u
Ct}rj-L<i
r%^XOw<'
private String sSiteURL; //Site's URL <W88;d33r=
private String sFilePath; //Saved File's Path kud2O>>
private String sFileName; //Saved File's Name gYfOa`k
private int nSplitter; //Count of Splited Downloading File MpLn)
" {Nw K
vz'<i. Yv4
public SiteInfoBean() k1M?6TW&
{//nSplitter的缺省值为5 $ 7uxReFZR
//default value of nSplitter is 5 60%EmX ;
this("","","",5); a:[m;
} LZrkFkiC
Kw,ln<)2
f{f|frs
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }o9(Q8
{ gj1l9>f>]a
sSiteURL= sURL; YX19QG%
sFilePath = sPath; O<6!?1|KP
sFileName = sName; z;[Z'_B
this.nSplitter = nSpiltter; =s[P =dU
?&r>`H E
RaY=~g
} i+Btz-
xm}`6B^f
qAR}D~t
public String getSSiteURL() cLCzLNyKl
{ p4I6oS`/.
return sSiteURL; ;gv9J[R
} DSx D531[A
vCtag]H2@
j8#B
public void setSSiteURL(String value) RBM4_L
{ *`.4M)Ym~
sSiteURL = value; ^)|1T#Tz
} E>6:59+
EL-1o02-
FR@##i$
public String getSFilePath() p&ml$N9fd
{ >VWH bo
return sFilePath; dsJHhsu6
} 3xz{[5<p
l<#*[TJ
Oy/+uw^
public void setSFilePath(String value) Nm]\0m0p-
{ ;l6tZ]-"
sFilePath = value; d>qxaX;
} NP*M#3$[
/K]<7
`[5QouPV
public String getSFileName() ,:QDl
{ W8 m*co
return sFileName; kf<5`8
} e.IKmH]z
i@M^9|Gh
;eRYgC
public void setSFileName(String value) xPi/nWl`|
{ s$ 2@|;
sFileName = value; *!*J5/b
} z2QZ;ZjvRS
;9hi2_luV
DEw_dOJ(
public int getNSplitter() H `V3oS~}
{ ?][2J
return nSplitter; uII:Y{G
} bNG;`VZ%
&&;ol}W
|E)Es!dr
public void setNSplitter(int nCount) v@0lTl_
{ oiq7I@Y`x
nSplitter = nCount; 89@e &h*
} siHS@S
} *kXSl73 k
*8uSy/l
DVNGV
/* l*|^mx^Q
**Utility.java <ealt
*/ <}3c%Q1
package NetFox; Fs_umy#
oOhm`7iy
*@q+A1P7@
public class Utility { V6,D~7
Eg"DiI)7
av(d0E}}b
public Utility() _$me.
{ )K8k3]y&
Ds$8$1=L=k
@xJ qG"
} dUtxG ~9
@+VvZc2Y
//线程睡眠 hv'~S
public static void sleep(int nSecond) b'^OW
{ {_1^ GIIS
try{ BYEqTwhT&
Thread.sleep(nSecond); \`#;J?Y|`F
} ,@=qaU
catch(Exception e) TR,,=3n
{ z= -u89]
e.printStackTrace (); zYdSg<[^
} h'<}N
} GV1\8OG7
Jp.Sow
//日志 "_ b Sy
public static void log(String sMsg) *$x/(!UE
{ . ({aPtSt!
System.err.println(sMsg); GBvB0kC)c
} UM7Ft"
*eL%[B
EA2BN}
public static void log(int sMsg) R:B-4
{ ?6B)Ek,'X?
System.err.println(sMsg); k+44ud.j
} EuqmA7s8A
} +&tY&dQQB
\~Zj](#
&by,uVb=|{
/* 673v
**TestMethod.java Y>EwU
*/ fyx-VXu
package NetFox; ?)1h.K1}M
F&;g< SD
"*#$$e53A
public class TestMethod { YWM$%
P6S^wjk
a9"x_IVU
public TestMethod() e}f!zA
{ ///xx/weblogic60b2_win.exe WE4:Jy
try{ B+ GPTQSTb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E@"+w,x)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y:G6Nd VFM
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0gHJ%m9s
fileFetch.start(); 5wRDH1z@{
} Q <^'v>~n
catch(Exception e){e.printStackTrace ();} B[C2uVEX:
q+dY&4&u
LcE!e%3
} y .S0^
]ss0~2
f`p`c*
public static void main(String[] args) 3w ?)H
{ VGM8&J{o'
new TestMethod(); =nA;,9%
} %#02Z%?%
} :doP66["!
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