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)); 02 FLe*zQ
} QVn2`hr
for(int i=0;i<nEndPos.length-1;i++) 5hqXMs
{ TrZ!E`~
nEndPos = nStartPos[i+1]; 0gyvRM@ x[
} <S_0=U
nEndPos[nEndPos.length-1] = nFileLength; =}ZY`O*/
} w2$ L;q
} ?:q"qwt$F
0#c-qy
jHMP"(]
//启动子线程 K[SzE{5=P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Uq=Rz8hLM
for(int i=0;i<nStartPos.length;i++) MPp:EH
{ ;[zZI~wh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vU/sQt8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %to.'R
nStartPos,nEndPos,i); )p!") :'fv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h1)+QLI
fileSplitterFetch.start(); 4YOLy\"S
} E=v4|/['N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Kmxo4p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GNG.N)q#C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C#&b`
nEndPos = " + nFileLength); bz&9]%S<
// fileSplitterFetch[nPos.length-1].start(); 'o_ RC{k2"
I%?M9y.u6
?`*`A9@
//等待子线程结束 J_ h\tM
//int count = 0; acpc[^'
//是否结束while循环 <!u(_Bxw/
boolean breakWhile = false; DL_M#c`<
EY1L5Ba.
L8;`*H
while(!bStop) "| oW6@
{ rI:]''PR
write_nPos(); I1ibrn
Utility.sleep(500); -r_Pp}s
breakWhile = true; B*Q.EKD8s
I7ySm12}
+c'I7bBr
for(int i=0;i<nStartPos.length;i++) 7 dG_E]&
{ ^w RD|
if(!fileSplitterFetch.bDownOver) t/"9LMKs?
{ (+\K
breakWhile = false; {XS2<!D
break; ku5g`ho
} vCR\lR+
} 1 pzd
if(breakWhile) [h :FJ
break; :n?}G0y
0xutG/-&N
Ks7kaX
//count++; 7w"YCRKh
//if(count>4) p4zV<qZ>e
// siteStop(); [TpW$E0H
} i `8Y/$aT
w*N9p8hb]
jr5x!@rb
System.err.println("文件下载结束！"); "V_PWEi
} Y)4D$9:
catch(Exception e){e.printStackTrace ();} |c>A3 P$=B
} t#g6rh&
}oTac
;c>Rjg&[
//获得文件长度 K>$od^f%c
public long getFileSize() seH#v
{ *SZ*S%oS3
int nFileLength = -1; M*c`@\
try{ aKCXV[PO
URL url = new URL(siteInfoBean.getSSiteURL()); >&9Iy"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {z%%(,I
httpConnection.setRequestProperty("User-Agent","NetFox"); v4<x 4
ex2*oqAdX
L``K. DF
int responseCode=httpConnection.getResponseCode(); yyHr. C
if(responseCode>=400) Om2 )$(
{ UIv 2wA2
processErrorCode(responseCode); 'x10\Q65[
return -2; //-2 represent access is error |5,q54d(K
} R\=y/tw0H
F3a"SKMW
D &wm7,
String sHeader; *%cI,}%
T3{qn$t8
FyQ^@@
for(int i=1;;i++) DI!l.w5P_
{ D`.CXFI+U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gGdZ}9
//Utility.log(in.readLine()); UeT"v?zP
sHeader=httpConnection.getHeaderFieldKey(i); ^f1}:g
if(sHeader!=null) R16"lG
{ ? B^*YCo7(
if(sHeader.equals("Content-Length")) g;bkVq
{ 1}!f.cWV(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =N n0)l
break; H1=R(+-s
} ]0dp^%
} rYq8OZLi
else ?(U> )SvF
break; TZZqV8
} c-avX
} Dx Vt
catch(IOException e){e.printStackTrace ();} W~Mj6c~S"
catch(Exception e){e.printStackTrace ();} .)u,sYZA|
$- #M~eZv
iygdX2
Utility.log(nFileLength); e v?Hz8Q;(
Mi'eViH
:ZU
return nFileLength; #ZGWU_l}
} K=Fcy#,f
Khw!+!(H
+|( eP_
//保存下载信息（文件指针位置） R_4600
private void write_nPos() /tP"r}l
{ 0/(YH
try{ vC J
output = new DataOutputStream(new FileOutputStream(tmpFile)); R`>E_SY
output.writeInt(nStartPos.length); Nc]oAY
for(int i=0;i<nStartPos.length;i++) UXa3>q>
{ 6z=:x+m
// output.writeLong(nPos); m=NX;t
output.writeLong(fileSplitterFetch.nStartPos); /2?GRwU~P
output.writeLong(fileSplitterFetch.nEndPos); {u46m
} l!q i:H<=1
output.close(); ycCEXu2F
} 4"wuqr|o
catch(IOException e){e.printStackTrace ();} R4QXX7h!
catch(Exception e){e.printStackTrace ();} {?BxVDD07
} tM]qR+
='OPU5(;O
'ei9* 4y
//读取保存的下载信息（文件指针位置） aCFO]
private void read_nPos() Sjj&n S
{ o $p*C
try{ S4`uNB#Ht
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MWsBZJRr
int nCount = input.readInt(); =}U`q3k
nStartPos = new long[nCount]; W)w@ju$Ko
nEndPos = new long[nCount]; kV6T#RVob
for(int i=0;i<nStartPos.length;i++) ?OvtR:hC
{ ,p>=WX
nStartPos = input.readLong(); OES+BXGX
nEndPos = input.readLong(); }r*t V)
} IM)\-O\Wd
input.close(); (+bk +0
} E@P8-x'i
catch(IOException e){e.printStackTrace ();} xC!,v 0&
catch(Exception e){e.printStackTrace ();} zn>*^h0B
} d5+ (@HSR
:%)l*[
AXz'=T}{
private void processErrorCode(int nErrorCode) XrtB&h|C
{ &FIPEe#n
System.err.println("Error Code : " + nErrorCode); 4wMKl6mL
} r/+<_3
W9{6?,]
6 }qNH29
//停止文件下载 E,u@,= j
public void siteStop() Yep(,J~'
{ P0DvZV8
bStop = true; #:w/vk
for(int i=0;i<nStartPos.length;i++) M8:gHjwsx
fileSplitterFetch.splitterStop(); @q],pD
Pfe&wA't
S;MS,R
} g O,X
} QrHI}r
//负责部分文件的抓取 D#1'#di*t
**FileSplitterFetch.java 'kL>F&|
*/ DL_2%&k/
package NetFox; N3TkRJZ
t+W+f
/^ hB6_'D
import java.io.*; 7y&Fb
import java.net.*; +kd88Fx
oXK`=.\
J}hi)k
public class FileSplitterFetch extends Thread { $e_A( |
>mgbs>
wtndXhVC4>
String sURL; //File URL 's8NO Xlj
long nStartPos; //File Snippet Start Position %XMrSlSOp
long nEndPos; //File Snippet End Position 3YR6@*!f/
int nThreadID; //Thread's ID [kMXr'TyPX
boolean bDownOver = false; //Downing is over PBTGN;y
boolean bStop = false; //Stop identical Y]0oF_ :7
FileAccessI fileAccessI = null; //File Access interface !r,ZyJU
iKu[j)F
PnJr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2(YZTaY
{ _~d C>`K
this.sURL = sURL; KIps{_J[<
this.nStartPos = nStart; t^)q[g
this.nEndPos = nEnd; #9,!IW]l
nThreadID = id; {l-,Jbfi`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gz;().{
} |qE"60&"}
d7g/s'ZHt6
^VR1whCrx
public void run() >&f .^p
{ i44UqEb
while(nStartPos < nEndPos && !bStop) '""qMRCm
{ 2^Tj7@
R4"["T+L`
7]_UZ)u
try{ OY*BVJ^
URL url = new URL(sURL); Uq 2Uv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +[V[{n
httpConnection.setRequestProperty("User-Agent","NetFox"); su<_?'uH
String sProperty = "bytes="+nStartPos+"-"; g^26Gb.
httpConnection.setRequestProperty("RANGE",sProperty); &THM]3:
Utility.log(sProperty); L}ud+Wfox
8)&H=#E
C"PN3>x}j
InputStream input = httpConnection.getInputStream(); 6A7UW7/
//logResponseHead(httpConnection); #m1e_[
2mP| hp?
: FF:{&d
byte[] b = new byte[1024]; [-bL>8
int nRead; AMA:hQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ih!UL:Ckh
{ yHLclv
nStartPos += fileAccessI.write(b,0,nRead); M.1R]x(|
//if(nThreadID == 1) eC%.xu^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %?J\P@
} 9Xmb_@7b}
dt{|bQLu3
,miU'<8tQ|
Utility.log("Thread " + nThreadID + " is over!"); W%hdS<b
bDownOver = true; J)Dw`=O0n
//nPos = fileAccessI.write (b,0,nRead); Hq8<g$
} 3!`Pv ?|o
catch(Exception e){e.printStackTrace ();} di]z
} r.** z j
} "\Jq2vM
b[$%Wg
-v8Jn#f
//打印回应的头信息 $]:I1I
public void logResponseHead(HttpURLConnection con) S;M'qwN
{ d{0b*l%
for(int i=1;;i++) H@bra~k-
{ f/H rO6~k%
String header=con.getHeaderFieldKey(i); [Tby+pC
if(header!=null) zLc.4k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -`n>q^A7e
Utility.log(header+" : "+con.getHeaderField(header)); cEnkt=
else >Bq;Z}EV
break; I7r{&X) D
} d*,% -Io
} AT}}RE@vq
xcnHj1r-o'
yBE1mA:x7:
public void splitterStop() 8jd<|nYnfc
{ ji?0;2Y
bStop = true; 91r9RG>
} 25BW/23}e
p18-yt; 1
NoO>CjeFb
} 'Y(#Yxc
P0~3<h?U8
2!\y0*}K
/* 5#g<L ~
**FileAccess.java SKuZik_
*//文件访问(定位，写) [&|Le;h
package NetFox; Bwjd/id q
import java.io.*; V2g,JFp&
Ziuf<X{
kFgN^v^t
public class FileAccessI implements Serializable{ 7{RI`Er`
4q/E7n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Msn)jh
RandomAccessFile oSavedFile; >9a%"<(2#
long nPos; UBOCd[
R"6Gm67t
aO.'(kk8
public FileAccessI() throws IOException 9-o{[
{ auAST;"Z8
this("",0); )wP0U{7?v
} ^%~ztn 51
rtvuAFiH
Y:&1;`FBZ
public FileAccessI(String sName,long nPos) throws IOException JmrQDO_(
{ k^Tu9}[W1
oSavedFile = new RandomAccessFile(sName,"rw"); %2^C
this.nPos = nPos; l<PGUm:_
oSavedFile.seek(nPos); [POcO
} g,Kb9['
v|VY5vN
j$T2ff6
public synchronized int write(byte[] b,int nStart,int nLen) -le:0NUwI
{ $qD8vu )|j
int n = -1; F){f{-@)
try{ G(JvAe]r
oSavedFile.write(b,nStart,nLen); {-^>) iJqt
n = nLen; \cPGyeq
} <E$P
catch(IOException e) /AJ^wY
{ UL;d H
e.printStackTrace (); V J){@
} .Y_RI&B!L
m{mK;D
[4kx59J3b
return n; wz.Il-sm
} )jR:\fe
3Aaj+=]W
YM3oqS D
} }tft@,dIC
zN].W\("\
ETH`.~%
/* EM vV
**SiteInfoBean.java >G' NI?$
*/ PHDKx+$
package NetFox; lADi
cIl^5eE^Pq
_ H$Cm
public class SiteInfoBean { j0=`Jf
R{!s%K&
jV:U%
private String sSiteURL; //Site's URL <2A4}+p:
private String sFilePath; //Saved File's Path m f4@g05
private String sFileName; //Saved File's Name &wNN| fH
private int nSplitter; //Count of Splited Downloading File ?j8CkqX!
`U2PlCf|
rM[Ps=5
public SiteInfoBean() &_" 3~:N8k
{//nSplitter的缺省值为5 QV{Nq=%]
//default value of nSplitter is 5 T]Tz<w W(
this("","","",5); SnQ$
} F`Q,pBl1p6
"^_p>C)T
"kP.Kx!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l-t:7`=|
{ L4Nk+R;
sSiteURL= sURL; &JfyXM[]
sFilePath = sPath; >GT0x
sFileName = sName; D-ug$ZRg
this.nSplitter = nSpiltter; px4Z
hJFQ/(
Ba`]Sm=
} bI]1!bi]i
((.PPOdJV
]PUyX8'~
public String getSSiteURL() .]r[0U
{ U?#6I-
return sSiteURL; 'd(}bYr)
} 6K`frt
f$2lq4P{
.WyI.Y1
public void setSSiteURL(String value) y;<jE.7>
{ <LBMth
sSiteURL = value; k9}im
} j{p0yuZ)<
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"Jv&=zJ
public String getSFilePath() i]Kq
{ .YS[Md{
return sFilePath; 5fVdtJk7
} <6(u%t0k5
v+Mt/8
%eD&2$q*
public void setSFilePath(String value) `uzRHbJ`
{ l l&iMj]
sFilePath = value; Gc@ENE f
} I*ho@`U
uidE/7
r43dnwX
public String getSFileName() yGS._;#R
{ jRgv 8n
return sFileName; f, ;sEV
} 4=q\CK2^A
Bb-x1{t
W:9L!+m^
public void setSFileName(String value) ENqJ9%sk7
{ xhimRi
sFileName = value; A`OU}'v?L
} v{%2`_c
>aa-ix &
:=~([oSNW"
public int getNSplitter() Nk^#Sa?
{ y#x]?%m
return nSplitter; N:&^ql4
} !sR`]0
{0Leua
"]JS,g {m
public void setNSplitter(int nCount) C/]0jAAE7
{ @Vb-BC,
nSplitter = nCount; cT.1oaAM0
} T}4RlIZF
} "I+wU`AIek
CZbp}:|
-ud!j
/* ~~yo& ]
**Utility.java sq :ff
*/ BJ{mX>I(
package NetFox; _jnH!Mw
eb+[=nmP
L*L3;y|
public class Utility { BQw#PXp3
k6*2= xK~
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public Utility() .;$/nz6vk
{ \UN7lDH
3YRhqp"E
\mv7"TM
} G]5'U"cj3
,gRsbC
//线程睡眠 neOR/]
public static void sleep(int nSecond) 5$zC,g*#
{ vw+ @'+
try{ *a+~bX)18
Thread.sleep(nSecond); T_I"Tsv
} xJZbax[
catch(Exception e) IURi90Ir
{ "4L' 2w+
e.printStackTrace (); (5'qEi ea
} =">O;L.xj
} J6::(0HM
FtE%<QHt
//日志 (MbI8B>
public static void log(String sMsg) *S{%+1F
{ G~YV6??
System.err.println(sMsg); &HW%0lTs%
} ~fQ#-ekzqk
P3@[x
SRj|XCd
public static void log(int sMsg) 5H?`a7q N
{ B4&x?-0ZC
System.err.println(sMsg); Ok O;V6`
} 9I9J}&4
} ggX'`bK
v#D9yttO{
dkRJ^~
/* ,uuQj]Dac+
**TestMethod.java QJ pUk%Wj
*/ <W\~A$
package NetFox; Yc\;`C
~vaV=})
$NJi]g|<3
public class TestMethod { hwkol W
nQg6 j Zf
'du:Bxl`d4
public TestMethod() J%D'Xlb
{ ///xx/weblogic60b2_win.exe q4(&.Al\@
try{ "hpK8vQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b^^Cj(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6}{2W<
SiteFileFetch fileFetch = new SiteFileFetch(bean); _vvnxG!x&
fileFetch.start(); .ay K+6I
} c9iCH~
catch(Exception e){e.printStackTrace ();} WihOGdUS6
%E~4Ur
`h :&H,N
} I=Ws /+
j[) i>Qw
wxr93$v
public static void main(String[] args) g:e|
{ 56&s'
new TestMethod(); hSr#/dw&
} XQ,IEj|
} d/Fjs0pt
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