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)); axW3#3#`
} -yHVydu=
for(int i=0;i<nEndPos.length-1;i++) RUC V!L
{ *lRP ZN
nEndPos = nStartPos[i+1]; /Y_F"GQ
} TK<~(Dk
nEndPos[nEndPos.length-1] = nFileLength; dPwe.:
} 3 [: x#r
} $=uyZTYF)}
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d?C8rkV'
//启动子线程 qRT1Wre 3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +/y 3]}
for(int i=0;i<nStartPos.length;i++) M)C.bo{p
{ }2:/&H'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Nloa/a&9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Sd'!(M^k3
nStartPos,nEndPos,i); dtw1Am#Ci
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ; {$9Sc $
fileSplitterFetch.start(); SUsD)!u_H
} s,XKl5'+8e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +QT(~<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3YVG|Bc~_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n0q5|ES
nEndPos = " + nFileLength); r e.chQ6
// fileSplitterFetch[nPos.length-1].start(); Nlemb:'eP3
rT9<_<
uUu]JDdz
//等待子线程结束 ?W-J2tgss{
//int count = 0; [0U!Y/?6lA
//是否结束while循环 ;A7HEx
boolean breakWhile = false; Ymkk"y.w
5<\&7P3y
Y0fX\6=h
while(!bStop) o_ka'|
{ `VX]vumG
write_nPos(); >MZWm6M8
Utility.sleep(500); ac%%*HN,
breakWhile = true; L\_MZ*<0[
R`q*a_
mk.:V64 >;
for(int i=0;i<nStartPos.length;i++) +a_eNl,
{ ":E 7#9
if(!fileSplitterFetch.bDownOver) mJe;BU"y]
{ /{Ksi+q
breakWhile = false; .q$HL t
break; G{ ~pA4
} 01<~~6A
} 12BTZ
if(breakWhile) 0j\?zt?
break; Se7NF@>9_
xvOGE]n
j_Pt8{[
//count++; U?97yc\$
//if(count>4) c'B6E1}sx
// siteStop(); v1%rlP
} )X2=x^u*U
u~FXO[b
rt)70=
System.err.println("文件下载结束！"); &^$dHr6v
} fr kDf-P
catch(Exception e){e.printStackTrace ();} t<s:ut)Q!
} zBD ?O!
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L1ZhH3}X
//获得文件长度 yo]!Zn
public long getFileSize() %>Z;/j|#r
{ pi7Fd\A
int nFileLength = -1; (]7&][
try{ yk OJhd3
URL url = new URL(siteInfoBean.getSSiteURL()); Lsv[@Rl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Tk3@jw+b
httpConnection.setRequestProperty("User-Agent","NetFox"); #ky]@vyO
l6Wa~E
2Pn
int responseCode=httpConnection.getResponseCode(); /T&z :st0
if(responseCode>=400) TD:NL4dm
{ |;3Ru vX?+
processErrorCode(responseCode); Lh.?G#EM
return -2; //-2 represent access is error ?;Dh^mc
} /4{6`
ZD\`~I|gp
YCZl1ry:V=
String sHeader; cr Hd$~q,
&TYTeJ]
q8%T)$!
for(int i=1;;i++) )HbsUm#
{ $/^DY&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~?i;~S
//Utility.log(in.readLine()); 7pH`"$
sHeader=httpConnection.getHeaderFieldKey(i); (8DJf"}
if(sHeader!=null) ZYDLl8
{ a_Y*pOu
if(sHeader.equals("Content-Length")) dU%Q=r8R
{ <?UbzT7X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1%~yb Q
break; EUH&"8 L
} ^_W+
} &5>R>rnB
else G?D7R/0)
break; l",JN.w
} *6D0>F
} _aa3;kT_
catch(IOException e){e.printStackTrace ();} 1|$V
catch(Exception e){e.printStackTrace ();} 5u +U^D
'q%56WAJ
pleLdGq
Utility.log(nFileLength); ArWMbT>Zqw
6[fpe
xG:eS:iT
return nFileLength; eX7dyM
} ~/Gx~P]
=kvfe" N0e
HE GMwRJG
//保存下载信息（文件指针位置） g-`HKoKe
private void write_nPos() C "XvspJ
{ G|eY$5!i
try{ hu}`,2
output = new DataOutputStream(new FileOutputStream(tmpFile)); V5w00s5?%
output.writeInt(nStartPos.length); tGHZU^B:}
for(int i=0;i<nStartPos.length;i++) `x%v&>
{ jo 0 d#
// output.writeLong(nPos); 'z$BgXh\
output.writeLong(fileSplitterFetch.nStartPos); r}kQ<SRx
output.writeLong(fileSplitterFetch.nEndPos); &)`xlIw}
} i#Tm] ++
output.close(); &:1PF.)N
} So>P)d$8+
catch(IOException e){e.printStackTrace ();} x\taG.'zX
catch(Exception e){e.printStackTrace ();} (A!+$}UR
} X"_,#3Ko!
gc``z9@Xg
`o~dQb/k+
//读取保存的下载信息（文件指针位置） Ia_I~ U$
private void read_nPos() *Ju$A
{ Q72}V9I9
try{ WJH-~,u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fZ8%Z
int nCount = input.readInt(); ' >a(|
nStartPos = new long[nCount]; { FVLH:{U^
nEndPos = new long[nCount]; )I7~<$w
for(int i=0;i<nStartPos.length;i++) 4C@ .X[r
{ 3ZdheenK9
nStartPos = input.readLong(); b=nQi./f
nEndPos = input.readLong(); =`RogjbP
} #[ZF'9x
input.close(); Ik[aiz
} =!}n .
catch(IOException e){e.printStackTrace ();} Uedzt
catch(Exception e){e.printStackTrace ();} &o{=
} 'Cw&9cL9w
b[5$$_[
/ZC/yGdIS_
private void processErrorCode(int nErrorCode) -L%J,f[&,
{ qKoD*cl)Za
System.err.println("Error Code : " + nErrorCode); Uc oVp}vl
} kLc}a5;
%eJolztKZ
,H6*9!Dv2
//停止文件下载 qm RdO R
public void siteStop() u!kC+0Y
{ I*,!zym
bStop = true; tBR"sBiws
for(int i=0;i<nStartPos.length;i++) V>"nAh]}.
fileSplitterFetch.splitterStop(); hf5yTs
80qSPitj
yX%q7ex
} >q W_%
} c6 O1Z\M@\
//负责部分文件的抓取 kmfz=q?
**FileSplitterFetch.java J<K-Yeph
*/ -+1_ 1!
package NetFox; 7G,{BBB
1Z9_sd~/6
\#1*r'V8
import java.io.*; ]/byz_7]
import java.net.*; Fh2$,$ 2
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e,j2#wjor
public class FileSplitterFetch extends Thread { 5R^e
)ro3yq4??
~W?F.
String sURL; //File URL o}EipTL
long nStartPos; //File Snippet Start Position >%qk2h>
long nEndPos; //File Snippet End Position -P I$SA,
int nThreadID; //Thread's ID DeqTr:
boolean bDownOver = false; //Downing is over kR+xInDM*
boolean bStop = false; //Stop identical CKC%|xke
FileAccessI fileAccessI = null; //File Access interface ii0{$}eoh
:X1~
3O{*~D&n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?&qa3y)wX:
{ 1oD1ia#
this.sURL = sURL; |jh&a+4W
this.nStartPos = nStart; 4k}3^.#
this.nEndPos = nEnd; UNx|+
nThreadID = id; .I~#o$6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZkbaUIQ
} Gk"o/]Sf
7d9kr?3(U
~3]ZN'b\
public void run() 93Z/|7
{ f?KHp|
while(nStartPos < nEndPos && !bStop) p]/qf\E
{ U`{'-L.
"Jd!TLt\x
P'EPP*)q
try{ n^} -k'l
URL url = new URL(sURL); {_#~&IQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Az#dt]H
httpConnection.setRequestProperty("User-Agent","NetFox"); Z )Imj&;
String sProperty = "bytes="+nStartPos+"-"; |r5e#3w
httpConnection.setRequestProperty("RANGE",sProperty); kNC.^8ryz[
Utility.log(sProperty); XUI9)Ne
$-HP5Kj(k-
F0yvV6;
InputStream input = httpConnection.getInputStream(); g43j-[j)
//logResponseHead(httpConnection); 5AX AIPn)
{2|[7oNT6
z]/;?
byte[] b = new byte[1024]; j41)X'MgJ
int nRead; M4%u~Z:4h+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uc0 1{t0,
{ bfjC:"!H
nStartPos += fileAccessI.write(b,0,nRead); 0F"W~OQ6
//if(nThreadID == 1) ~&zrDj~FI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7(ni_|$|
} [w0@7p"7
,r=9$i_
U8f!yXF'
Utility.log("Thread " + nThreadID + " is over!"); +XaRwcLC.
bDownOver = true; YY!Lv:.7>
//nPos = fileAccessI.write (b,0,nRead); [r[IWy(}
} .f1
catch(Exception e){e.printStackTrace ();} }OQaQf9V{
} U9?fUS
} % oPt],>
tl:V8sYTP
d|P,e;m-
//打印回应的头信息 @W4tnM,#
public void logResponseHead(HttpURLConnection con) .G ^-.p
{ #hp7@ Tu
for(int i=1;;i++) 'H19@b5rx
{ gD13(G98
String header=con.getHeaderFieldKey(i); gdPPk=LD
if(header!=null) e8WuAI86
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J^!2F}:
Utility.log(header+" : "+con.getHeaderField(header)); RA%=_wPD +
else :i{Svb*_'
break; >i6sJ)2?>
} l**gM
} k-:wM`C
q <, b
11'^JmKA
public void splitterStop() JAQ y
{ d8)ps,
bStop = true; p`dH4y]D
} `Z#0kpXk_
#9(0.!v
@3^D[
} ?%|w?Fdx-
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1g{-DIOmn
/* Nldy76|g
**FileAccess.java u<g0oEs)
*//文件访问(定位，写) r<%ua6@
package NetFox; H^VNw1.
import java.io.*; S7B7'[ru
/?ZO-]q
|w{}h6a
public class FileAccessI implements Serializable{ ?Iin/<y
9wTN*y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >3C4S
RandomAccessFile oSavedFile; {h}0"5
long nPos; z[cs/x
c\Z.V*o
Y94^mt-
public FileAccessI() throws IOException s~z~9#G(6
{ }&*wJ]j`L
this("",0); *(,zPn,
} { R`"Nk
]ZMFK>"^%
Qm"&=<
public FileAccessI(String sName,long nPos) throws IOException ?rJe"TOIy
{ 8t)?$j$
oSavedFile = new RandomAccessFile(sName,"rw"); @TQzF-%#7
this.nPos = nPos; 18HmS>Qo
oSavedFile.seek(nPos); A2 r\=for
} eT'Z;ZO
hZ[(Ik]*Zd
|zkZF|-
public synchronized int write(byte[] b,int nStart,int nLen) zao=}j?
{ cIS?EW]S%X
int n = -1; A_4.>g
try{ A6?!BB=]
oSavedFile.write(b,nStart,nLen); tl=H9w&@
n = nLen; 1_jd1UT
} NimW=X;c
catch(IOException e) G<$N*3
{ ;4'pucq5/
e.printStackTrace (); x+;a2yE~
} F"ua`ercI
n^t!+
/$U<S"
return n; W5^<4Ya!
} ${F4x"x
+F4SU(T
q`0wG3
} -cONC9=
BN~gk~t_
S8dX8,qg
/* d7]~t|
**SiteInfoBean.java Yo*.? Mq'
*/ E]0}&YG
package NetFox; 9 WO|g[Y3
ls@j8bVv^
PB(q9gf"1}
public class SiteInfoBean { BY5ODc$
{8pN]=SaJ~
#]kO/Mr
private String sSiteURL; //Site's URL R_zQiSwG<
private String sFilePath; //Saved File's Path h]jy):9L
private String sFileName; //Saved File's Name a;h.I}*]
private int nSplitter; //Count of Splited Downloading File V#,jUH|
5hvg]w95;
UOa n
public SiteInfoBean() :pCv!g2
{//nSplitter的缺省值为5 P#l"`C /
//default value of nSplitter is 5 MJM<
this("","","",5); *~\R0ddz
} [e`e bn[C
)>]@@Trx
J=t@2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) SMn(c
{ 'Z8=y[l
sSiteURL= sURL; #8/pYQ;
sFilePath = sPath; V^%P}RFMc
sFileName = sName; od-yVE&
this.nSplitter = nSpiltter; fZgEJsr
L}\ oFjVju
EM7Z g 65
} b[rVr J
a{@gzB
Db K(Rh_ K
public String getSSiteURL() >pm`(zLn
{ E0)43
return sSiteURL; D$U`u[qjtS
} Pk{%2\%&2
d#CAP9n;'
&e\UlM22
public void setSSiteURL(String value) X.GK5Phd
{ uZml.#@4
sSiteURL = value; phi9/tO\u
} z'9U.v'M)
+`f3_Xd
<lgX=wx L
public String getSFilePath() vLs*}+f
{ c->.eL%
return sFilePath; (b8ZADI*
} :pdl2#5H^
85_Qb2<'r
[?55vYt
public void setSFilePath(String value) )m$MC25
{ ;-^8lWt
sFilePath = value; ~7>D>!!
} O_ d[{e=5`
lw43|_'G-t
%j/}e>$"Nk
public String getSFileName() lSG]{
{ a];1)zVA6
return sFileName; Ku?1QDhrF*
} rcz9\@M
vMzBp#MT
i:|e#$x
public void setSFileName(String value) _>E=.$
{ @y2cC6+'t
sFileName = value; oc"7|YG
} \DcO.`L
J,*+Ak ~
hrW2#v
public int getNSplitter() 8 .t3`FGH
{ %J8uVD.2
return nSplitter; Ip|=NQL>
} k_`h (R
U&W/Nj
snYyxi
public void setNSplitter(int nCount) [nf5<
{ L:\>)6]Ls
nSplitter = nCount; CrB4%W:{
} g&rz*)|/
} TPn#cIPG
PsM8J
cAq5vAqmg
/* p$}/~5b}4
**Utility.java X<Ag['r
*/ <+Gf!0i
package NetFox; jJD*s/o
e5d STc`
{dYz|O<
public class Utility { $;rvKco)%
?&=JGk^eJ
"?^#+@LV
public Utility() M<r]a{Yv
{ Gkm{b[
W~FU!C?]
*|ef#-|D
} 1&RB=7.h
Vqr]Ui
//线程睡眠 ar_@"+tZ
public static void sleep(int nSecond) jLn|zK
{ !JtM`x/yR
try{ B,] AfH
Thread.sleep(nSecond); 3oV2Ek<d
} pV O{7I
catch(Exception e) Y+h ?HS
{ f!F5d1N
e.printStackTrace (); 1\J9QZX0
} |rI;OvZ\
} 29zMs9oKPP
\U<d)j/
//日志 5w%[|%KG:L
public static void log(String sMsg) VRTJKi
{ Z23T2
System.err.println(sMsg); [6Q1yNE
} M)~sL1)
]X> I(p@
BO2s(8
public static void log(int sMsg) R$`%<Y3)
{ xDNXI01o
System.err.println(sMsg); &eb8k2S
} s>)?MB*vb
} h; 6G~D
fw5+eTQ^
PQUJUs
/* Z3U%Afl2{
**TestMethod.java 3WpQzuHPT
*/ 5uV_Pkb?8
package NetFox; w'9!%mr
7\N }QP0"u
Y`3\Z6KlV
public class TestMethod { [+L!c}#
RKZBI?@4
i-9W8A
public TestMethod() jX0^1d@
{ ///xx/weblogic60b2_win.exe <fE^S
try{ R@#xPv4o%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eVd:C8q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?*.:*A
SiteFileFetch fileFetch = new SiteFileFetch(bean); $y{.fjy3
fileFetch.start(); ;p7R~17
} T-h[$fxR_
catch(Exception e){e.printStackTrace ();} q/Zs]Gz
nzZs2
Sk-Q 4D^
} Lyz8DwZ
U'u_'5{
~NB|BwAh
public static void main(String[] args) CM7NdK?I
{ \58bz<u"
new TestMethod(); U "r)C;5
} ;NQ}c"9
} '<QFf
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