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)); Vt!<.8&`
} e;/C}sK:
for(int i=0;i<nEndPos.length-1;i++) IAJYD/Y&?
{ |rbl sL2?Z
nEndPos = nStartPos[i+1]; ax)j$
} :9Vd=M6,
nEndPos[nEndPos.length-1] = nFileLength; -=A W. Zo
} ;dh8|ujh
} a|v}L,
Jqt&TqX@s
>`@yh-'r
//启动子线程 S=wJ{?gzAK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; njy^<7;
for(int i=0;i<nStartPos.length;i++) 2iM8V
{ n_Ka+Y<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), AIXvS*Y,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WZ<kk T
nStartPos,nEndPos,i); OLdD3OI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U8b1 sz
fileSplitterFetch.start(); -MqWcB9&
} F}lgy;=h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E(&GZ QE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G2,r%|7ta
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ph&fOj=pFb
nEndPos = " + nFileLength); XI*_ti
// fileSplitterFetch[nPos.length-1].start(); C;jV{sb9c
{&Bpf K;`)
;\$P;-VY
//等待子线程结束 /@.c 59r
//int count = 0; !^|%Z
//是否结束while循环 VnJ-nfA
boolean breakWhile = false; ab=s+[r1
hR$lX8
%YaUc{.%
while(!bStop) ?"aj&,q+
{ iZy`5
write_nPos(); /Lc= K<
Utility.sleep(500); 2z\4?HJy
breakWhile = true; Uq,M\V\
$pT%7jV}
<}E^r_NvD
for(int i=0;i<nStartPos.length;i++) IFX|"3[$
{ [wM<J$=2
if(!fileSplitterFetch.bDownOver) m7XJe[O
{ a#0GmK
breakWhile = false; /Jc?;@{
break; yt&eY6Xp
} wnE c
} $<UX/a\sH
if(breakWhile) 1@ j>2>i
break; G=8w9-Ww
>t"]gQHtx
jj)9jUz
//count++; !k&~|_$0@
//if(count>4) Te8BFcJG
// siteStop(); id-VoHdK
} !j(KbAhWZ
MGO.dRy_
p0.?R
System.err.println("文件下载结束！"); LC/w".oq?
} ^/W7Xd(s
catch(Exception e){e.printStackTrace ();} hG,gY;&[6
} 2.2Z'$W
<(JsB'TK
n/"T7Y\2
//获得文件长度 j}R4mh
public long getFileSize() !40t:+I
{ I`%=&l[v_5
int nFileLength = -1; wYf=(w\c
try{ ] %*970
URL url = new URL(siteInfoBean.getSSiteURL()); y0qE::/H$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vtFA#})~
httpConnection.setRequestProperty("User-Agent","NetFox"); a{h(BI^~
#^Dc:1,
xQ7n$.?y@
int responseCode=httpConnection.getResponseCode(); K]bS:[34 R
if(responseCode>=400) We]X+>BlO
{ ~MY(6P
processErrorCode(responseCode); 13Z6dhZu
return -2; //-2 represent access is error hh"0z]
} );h\0w>3
qD\%8l.]Z
(nrrzOax
String sHeader; AEwb'
{K'SOhH4?
8mA6l0
for(int i=1;;i++) |4Ix2GD
{ 04;y%~,}U/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ABV\:u
//Utility.log(in.readLine()); ,l<-*yMD
sHeader=httpConnection.getHeaderFieldKey(i); 2vnzB8"k
if(sHeader!=null) FGx_qBG4|
{ dITnPb)i
if(sHeader.equals("Content-Length")) %:o@IRTRU
{ +^+wS`Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x#0C+cU
break; 2al~`
} x=B+FIJ
} ) Q=G&
else <nsl`C~6g0
break; p8"(z@T
} "|DR"rr'j
} 9L#B"lh
catch(IOException e){e.printStackTrace ();} )C2d)(baEJ
catch(Exception e){e.printStackTrace ();} f 5i`B*/
=zA=D.D2
-R'p^cMA
Utility.log(nFileLength); 7IJb$af:;
%Z{J=
gSj-~kP
return nFileLength; CHpDzG>]4
} sW2LNE
`^J~^Z7Y-
,H[AC}z2X
//保存下载信息（文件指针位置） r-YQsu&
private void write_nPos() Vd<= y
{ [bPE?_a,
try{ J-PzIFWd
output = new DataOutputStream(new FileOutputStream(tmpFile)); <vt^=QA'
output.writeInt(nStartPos.length); )dL?B9d:
for(int i=0;i<nStartPos.length;i++) rF0zGNH
{ ($(1KE
// output.writeLong(nPos); *vAOUqX`x
output.writeLong(fileSplitterFetch.nStartPos); g&0GO:F`
output.writeLong(fileSplitterFetch.nEndPos); 4_.k Q"'DH
} J|FyY)_
output.close(); &<Gq-IN
} 1]>KuXd r
catch(IOException e){e.printStackTrace ();} j|G-9E
catch(Exception e){e.printStackTrace ();} oZCi_g 5i
} g41Lh3dj
gy =`cMS@
`4EOy:a
//读取保存的下载信息（文件指针位置） NuO>zAu
private void read_nPos() <uTsXv
{ <Z8] W1)
try{ hTG d Uw]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6vaxp|D
int nCount = input.readInt(); $g$`fR)
nStartPos = new long[nCount]; )ql?}
nEndPos = new long[nCount]; #6H<JB
for(int i=0;i<nStartPos.length;i++) pn $50c
{ J#x91Jh
nStartPos = input.readLong(); w|nVK9.
nEndPos = input.readLong(); EhFhL4Xdn
} 93WYZNpX
input.close(); Ba+OoS
} Fcr@Un'
catch(IOException e){e.printStackTrace ();} fd,~Yj$R?
catch(Exception e){e.printStackTrace ();} oM7^h3R
} lwg.'<
;W+-x]O
x b0+4w|
private void processErrorCode(int nErrorCode) }\0"gM
{ *i?qOv/=>
System.err.println("Error Code : " + nErrorCode); `X^e}EGWu
} YqJIp. Z
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n#&RY%#`
//停止文件下载 xRY5[=97
public void siteStop() 'j)eqoj
{ D1Sl+NOV
bStop = true; E7h}0DX
for(int i=0;i<nStartPos.length;i++) wKeqR$
fileSplitterFetch.splitterStop(); "G,*Z0V5
%@&)t?/=
|fI%L9
} ^r& {V"l]
} ?0(B;[xEJ
//负责部分文件的抓取 cY"^3Ot%^
**FileSplitterFetch.java *tO<wp&
*/ z>0"T2W y
package NetFox; (;j7{(
]s -6GT
K`X2N
import java.io.*; #`fT%'T!
import java.net.*; xqtjtH9X
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"/'=gE
public class FileSplitterFetch extends Thread { k`AJ$\=
>gSerDH8\
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String sURL; //File URL j&Aq^aI
long nStartPos; //File Snippet Start Position F:@Ixk?E
long nEndPos; //File Snippet End Position }6bLukv
int nThreadID; //Thread's ID piG1&*
boolean bDownOver = false; //Downing is over Ji!-G4.n"
boolean bStop = false; //Stop identical 1%@~J\qF
FileAccessI fileAccessI = null; //File Access interface Qm.kXlsDI
0\#Q;Z2
@ tIB'|O
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |:#mw1
{ E nvs[YZe
this.sURL = sURL; 31*6 ;(
this.nStartPos = nStart; flB,_
this.nEndPos = nEnd; \+uqP:Ty
nThreadID = id; X2uX+}h*tA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [dJ\|=
} EC~t'v
JB(;[#'~
R,\ r{@yrz
public void run() LNZ#%R~r
{ ?},ItJ#>)q
while(nStartPos < nEndPos && !bStop) uJOW%|ZN`
{ _5T7A><q<
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t4IJ%#22
try{ Rpk`fxAO
URL url = new URL(sURL); 5G<CDgl^!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4cQ5E9
httpConnection.setRequestProperty("User-Agent","NetFox"); mvgm o
String sProperty = "bytes="+nStartPos+"-"; Flxo%g};
httpConnection.setRequestProperty("RANGE",sProperty); `0^i #
Utility.log(sProperty); Ng"vBycy
i-?zwVmn
RNdnlD#P
InputStream input = httpConnection.getInputStream(); y2R=%EFh6
//logResponseHead(httpConnection); j1F+,
%-l:_A
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byte[] b = new byte[1024]; OD]J@m
int nRead; BB.TrQM.#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a+/|O*>#
{ >y9o&D
nStartPos += fileAccessI.write(b,0,nRead); \`zG`f
//if(nThreadID == 1) yU|ji?)e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uB1!*S1f
} fqb$_>3Ol
C.E>)
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Utility.log("Thread " + nThreadID + " is over!"); kMl<
bDownOver = true; $t$f1?
//nPos = fileAccessI.write (b,0,nRead); N >!xedw=
} gJ.6m&+
catch(Exception e){e.printStackTrace ();} 1J"9r7\
} pYVy(]1I(3
} -YV4 O
X=pt}j,QrP
^qqHq
//打印回应的头信息 ?Q)Z..7
public void logResponseHead(HttpURLConnection con) winJ@IYW
{ C/waH[Yzan
for(int i=1;;i++) ?0mJBA
{ 0lCd,a2:
String header=con.getHeaderFieldKey(i); RuNH (>Eb
if(header!=null) p^rX.?X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~5uNw*H
Utility.log(header+" : "+con.getHeaderField(header)); 6wB>-/'Y
else 0NtsFPO
break; _-\s[p5
} ZPsY0IzLo
} ?0NSjK5ma
2w|u)ow)
9'q/&uH
public void splitterStop() !>y}Xq{bm3
{ +)JqEwCrq
bStop = true; |u;BAb
} TDIOK
hu(K!>{
`_U0>Bfg;
} FRt/{(jro
Zk#i9[g9*
y]]Vp~R:[
/* ^Cn]+0G#C8
**FileAccess.java ff1B)e
*//文件访问(定位，写) 0~b6wuFl
package NetFox; !7`=rT&
import java.io.*; j' KobyX<
d4>-a^)V
z%3"d0
public class FileAccessI implements Serializable{ = )l:^+q
"!Oh#Vf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DUKmwKM"k
RandomAccessFile oSavedFile; yr9A0F0
long nPos; aE+$&_>ef
pZ~>l=-
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public FileAccessI() throws IOException $t# ,'M
{ XjZao<?u
this("",0); BMWeD
} jnp6qpY{
%[\x%m)
Z*(!`,.bB
public FileAccessI(String sName,long nPos) throws IOException _K}_h\e.
{ 5m USh3
oSavedFile = new RandomAccessFile(sName,"rw"); ^xw [d}0S
this.nPos = nPos; +.#S[G
oSavedFile.seek(nPos); `J#xyDL6?
} l[ ": tG
&iiK ZZ`_o
!BQ ELB$0
public synchronized int write(byte[] b,int nStart,int nLen) K: o|kd
{ ;=VK_3"
int n = -1; bC4*w O
try{ @52=3
oSavedFile.write(b,nStart,nLen); /N[o[q
n = nLen; Ed&,[rC
} Na 9l#
catch(IOException e) $ lsRg:J
{ .V 3X#t
e.printStackTrace (); PP[)h,ZL*
} KT;C RO>
$F@L$&~
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return n; zNr_W[
} 76_8e{zbr
}RN=9J
MZMS?}.2
} N 1f~K.e\
.H(}[eG_
oF b mz*
/* 7{+Io
**SiteInfoBean.java `b#nC[b6|v
*/ X:SzkkVl7
package NetFox; $Y 4ch ko
gc2|V6(
Y6<0%
public class SiteInfoBean { u5XU`!
Z!RRe]"y
`YmI'
private String sSiteURL; //Site's URL \B>[je-d
private String sFilePath; //Saved File's Path )_Xxk_
private String sFileName; //Saved File's Name t`8e#n 9
private int nSplitter; //Count of Splited Downloading File \|pK Z6*s
nL+YL
W:{PBb"x8
public SiteInfoBean() 1_j<%1{sZ
{//nSplitter的缺省值为5 Tu=eQS|'
//default value of nSplitter is 5 BV }(djx
this("","","",5); x)#<.DX
} $-fjrQ
0bPJEEd
{F(-s"1;xO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $O~F>.*
{ K+7yUF8XP
sSiteURL= sURL; ,LW(mdIe(
sFilePath = sPath; q(&^9"
sFileName = sName; _]=TFz2O
this.nSplitter = nSpiltter; cEdz;kbUM
@u"kX2>Eq
C?/r}ly<\
} C;)Xwm>e
8!&ds~?
}W@#S_-e8
public String getSSiteURL() ,Og[[0g
{ VO @ 4A6
return sSiteURL; lNA'M&
} EN-8uY.
/HjI=263
fUp|3bBE
public void setSSiteURL(String value) }/7.+yD
{ CFkW@\]
sSiteURL = value; fbHWBb
} k67i`f=
XMeL^|D
/]k ,,&
public String getSFilePath() STXqq[+Rf
{ gf3u0' $
return sFilePath; <(#xOe
} `b^#quz
oA!5dpNhU
- 5o<Q'(
public void setSFilePath(String value) k}I5x1>&
{ mI?* Z%>g
sFilePath = value; 7}#*3*]
} '.%iPMM
W>q*.9}Y"
5I)~4.U|,m
public String getSFileName() ~ F?G5cN5
{ t-eKruj+
return sFileName; _#J_$CE#
} P^K?E
"LP, TC
1IOo?e=/bM
public void setSFileName(String value) QLF,/"
{ 2<y}91N:
sFileName = value; n!kk~65|
} XQ0#0<
u5cVz_S
To#E@Nw
public int getNSplitter() Nh1e1m?
{ zt)p`kdD
return nSplitter; L)kb (TH
} (<]\,pP0_
u|m[(-`
o;M.Rt\A
public void setNSplitter(int nCount) ,<0Rf
{ RI[7M (
nSplitter = nCount; }J+ce
} HO%E-5b9
} 9:9N)cNvfX
?$30NK3G
.q5J^/kr
/* 54ak<&?
**Utility.java r3+<r<gs
*/ aW`:)y&f
package NetFox; *} *!+C3
QQ^Gd8nQ
L~*|,h
public class Utility { w|!YoMk+o
nV!2Dfd
Xk{!' 0
public Utility() _Hz~HoNU
{ ? -v
,h%D4EVx
L\/u}]dPQ
} SWNU1x{,c\
3o+KP[A
//线程睡眠 L?=#*4t
public static void sleep(int nSecond) {f`lSu
{ _L&n&y1+%
try{ hw&ke$Fg#
Thread.sleep(nSecond); eW\?eq+ `A
} Ph(]?MG\_
catch(Exception e) XysFwi
{ k%EWkM)?
e.printStackTrace (); 2gQY8h8
} Pcs^@QP
} L Yh@ u1p
pchQ#GU
//日志 4o1Q7
public static void log(String sMsg) :0 W6uFNOU
{ tx^92R2/
System.err.println(sMsg); +Od1)_'\D3
} `FZ(#GDF
K)<Wm,tON
b\SXZN)Be
public static void log(int sMsg) dIoF~8V
{ l?3vNa FeR
System.err.println(sMsg); /M0l p
} 5xh!f%6
} @Ufa-h5"(
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G"G{AS
/* SL[rn<x|
**TestMethod.java :wQC_;
*/ -rEeKt
package NetFox; Zij"/gx\
7!O^;]+,
Nc G,0K
public class TestMethod { KotPV
+90u!r^v
@PYW|*VS
public TestMethod() E)KB@f<g*
{ ///xx/weblogic60b2_win.exe f:_=5e +
try{ Oq #o1>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :~\LOKf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UJ7'JBT=k
SiteFileFetch fileFetch = new SiteFileFetch(bean); +:Lk^Ny
fileFetch.start(); T$:>*
} ?cqicN.+6
catch(Exception e){e.printStackTrace ();} gJ]Cq/gC
DBQOxryP>o
5."5IjZu
} {F;,7Kn+l
X}3P1.n:
l'|E,N>X
public static void main(String[] args) \BN|?r$a
{ ^H'hD
new TestMethod(); J9g|#1G
} @''&nRC1
} w@87]/4Rq
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