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)); QvZ"{
} FJtmRPP[r
for(int i=0;i<nEndPos.length-1;i++) _`?cBu`
{ (yP1}?
nEndPos = nStartPos[i+1]; d9v66mpJM
} <?7qI85OT
nEndPos[nEndPos.length-1] = nFileLength; IsI5c
} yHw @Z
} m)p|NdTZc8
D}y W:Pi'
ZDmL?mC
//启动子线程 y7F |v8bq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 90W=v*
for(int i=0;i<nStartPos.length;i++) }[JB%
{ D8L5t<^1R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D2&d",%&f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xcW\U^1d
nStartPos,nEndPos,i); K{DC{yLu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N=1ue`i
fileSplitterFetch.start(); ZEI)U, I.
} C5dM`_3L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c%pf,sm'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $~FZJ@qa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Hj{.{V
nEndPos = " + nFileLength); 8*0QVFn$
// fileSplitterFetch[nPos.length-1].start(); Bp7p X
iuY,E
xS1n,gTA
//等待子线程结束 USyc D`
//int count = 0; )v;O2z
//是否结束while循环 B=d<L^
boolean breakWhile = false; I+kAy;2
S~aWun
K-k!':K:
while(!bStop) <Tgy$Hm
{ ulsU~WW7r
write_nPos(); 8<Iq)A]'Z
Utility.sleep(500); % vUU Fub
breakWhile = true; I9qZE=i
_rYW|*cIF
s;TB(M~i[
for(int i=0;i<nStartPos.length;i++) r!Dk_|Cd
{ 8C3oi&av/{
if(!fileSplitterFetch.bDownOver) -yqgs>R(d
{ A3/[9}(U
breakWhile = false; gDU!dT
break; @lj|
} `qhT
} <h:xZtz
if(breakWhile) zr?s5RS
break; 7!AyLw
j<(E%KN3
0V<kpC,4
//count++; kMVr[q,MEq
//if(count>4) O`y3H lc
// siteStop(); GLO3v. n;
} -b^dK)wR~
>} 2C,8N
ys=} V|
System.err.println("文件下载结束！"); bfA>kn0C
} Qg/FFn^Kg*
catch(Exception e){e.printStackTrace ();} l0,VN,$Yl
} y5eEEG6
UnK7&Uo
a4ViVy
//获得文件长度 ;iiCay37F
public long getFileSize() h_4*?w
{ p48enH8CO
int nFileLength = -1; q3#[6!
try{ nvndgeSy
URL url = new URL(siteInfoBean.getSSiteURL()); WCsf_1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GrG'G(NQ
httpConnection.setRequestProperty("User-Agent","NetFox"); gV.?Myy
^o5;><S]
rB".!b
int responseCode=httpConnection.getResponseCode(); 1+*sEIC"
if(responseCode>=400) 5/nL[4Z
{ 2ul8]=
processErrorCode(responseCode); HU>>\t?d
return -2; //-2 represent access is error m)L50ot:/
} ."ZG0Zg
rNV3-#kU
5c::U=
String sHeader; *90dkJZ.
_33b %
b_TI_
for(int i=1;;i++) ljK?2z>
{ `]W9Fj<1j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :-jbIpj'
//Utility.log(in.readLine()); H14Q-2U1xa
sHeader=httpConnection.getHeaderFieldKey(i); a9e0lW:=c
if(sHeader!=null) >G|RVB
{ B$rhsK%
if(sHeader.equals("Content-Length")) x"q]~u<rB
{ H-pf8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K^<?LXJF
break; H[.)&7M\
} *xxk70Cb
} ^Saf z8-3o
else /lECgu*#69
break; K[iAN;QCe%
} ]|!|3lQ
} }iKjef#J
catch(IOException e){e.printStackTrace ();} ~B{08%|oK
catch(Exception e){e.printStackTrace ();} 7<WUjK|
A2gFY}
j?u1\<m
Utility.log(nFileLength); ;7s^slVzF
_{'[Uf/l
+m./RlQ{
return nFileLength; jz" >Kh.}
} 8zHx$g
v K{2
t,De/L
//保存下载信息（文件指针位置） vNjc
private void write_nPos() [z!m
{ r2#G|/=@
try{ lUjZ=3"'
output = new DataOutputStream(new FileOutputStream(tmpFile)); L~PiDQr?r
output.writeInt(nStartPos.length); {g nl6+j
for(int i=0;i<nStartPos.length;i++) QP\:wi
{ #$W5)6ch
// output.writeLong(nPos); 1"CWEL`i
output.writeLong(fileSplitterFetch.nStartPos); ?rOj?J9
output.writeLong(fileSplitterFetch.nEndPos); `WH$rx!
} 2+y wy^
output.close(); ied1+H
} >g !Z|ju
catch(IOException e){e.printStackTrace ();} b/[X8w'VP
catch(Exception e){e.printStackTrace ();} 'sZGLgT;m
} -KC@M
@}6<,;|DQ
H,TApF89A
//读取保存的下载信息（文件指针位置） "=DQ {(L
private void read_nPos() WwsNAJ
{ 3\RD%[}
try{ ;O)*!yA(GG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e^N~)Nlj
int nCount = input.readInt(); #"-_~
nStartPos = new long[nCount]; KH#z=_
nEndPos = new long[nCount]; JfkEJk<
for(int i=0;i<nStartPos.length;i++) ~9o@1TO:v
{ _5S0A0
nStartPos = input.readLong(); KC}G_"f.$
nEndPos = input.readLong(); gnZ#86sO
} J=Kv-@I>E
input.close(); Mw,]Pt6~i
} s/@uGC0>
catch(IOException e){e.printStackTrace ();} pBe1:
catch(Exception e){e.printStackTrace ();} dCM&Yf}K
} MD$W;rk(Hn
mRAt5a#is
k(RKAFjY
private void processErrorCode(int nErrorCode) K@e2%hk9x
{ HYO/]\al
System.err.println("Error Code : " + nErrorCode); +)yoQRekX
} [nHN@p|
v\bWQs1
axmq/8X
//停止文件下载 l4T[x|')M
public void siteStop() 1v:Ql\^cT
{ 4I&(>9 @z<
bStop = true; YSxr(\~j
for(int i=0;i<nStartPos.length;i++) 8 !:2:
fileSplitterFetch.splitterStop(); &i3SB[|
G HQ~{
GmNCw5F
} e~gNGr]L/
} ^`#7(S)a/
//负责部分文件的抓取 b0'}BMJ
**FileSplitterFetch.java q1xSylE
*/ ;iYCeL(
package NetFox; .BxQF
6, j60`f)
<;#gcF[7>
import java.io.*; Qa/1*Mb
import java.net.*; Da)p%E>Q
-flcB|I`
f{2UL ?y
public class FileSplitterFetch extends Thread { +a,#BSt
#QsJr_=
Hc8^w6S1@
String sURL; //File URL 82 |^o
long nStartPos; //File Snippet Start Position "Ia.$,k9
long nEndPos; //File Snippet End Position J#H,QYnf(L
int nThreadID; //Thread's ID yz0#0YG7
boolean bDownOver = false; //Downing is over 5-0&`,
boolean bStop = false; //Stop identical 8fi'"
FileAccessI fileAccessI = null; //File Access interface OU` !c[O
E8PwA.
*MfH\X379
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mEYfsO
{ P%&|?e~D^
this.sURL = sURL; 9[\do@
this.nStartPos = nStart; 7./WS,49
this.nEndPos = nEnd; I/upiqy
nThreadID = id; aC'6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g:~q&b[q6
} v B~VJKD
!oi {8X@
9ec?L
public void run() ye(av&Hn
{ %VB4/~ "
while(nStartPos < nEndPos && !bStop) Ys_LGfK
{ o1\N)%
4sSw7`
_l] 0V g`
try{ D]fgBW-
URL url = new URL(sURL); .nEMd/pX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ar~<l2,{r
httpConnection.setRequestProperty("User-Agent","NetFox"); d]K8*a%[-
String sProperty = "bytes="+nStartPos+"-"; ,Gbc4x
httpConnection.setRequestProperty("RANGE",sProperty); Ha]vG@?+
Utility.log(sProperty); 416}# Mk
Pbbi*&i
}LS.bQKqi,
InputStream input = httpConnection.getInputStream(); ?`Mk$Y%my
//logResponseHead(httpConnection); |Wck-+}U
,_V/W'
z@ZI$.w
byte[] b = new byte[1024]; J"h2"$v,
int nRead; 7gOu|t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pk'd&.
{ uj\&-9gEi
nStartPos += fileAccessI.write(b,0,nRead); 4VvE(f
//if(nThreadID == 1) Y5ei:r|^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cGo_qR/B(>
} hFtjw6
_d7;Z%
yYe>a^r4R
Utility.log("Thread " + nThreadID + " is over!"); y+$vHnS/jC
bDownOver = true; wPYeKOh'
//nPos = fileAccessI.write (b,0,nRead); "fv+}'
} mHW%^R=
catch(Exception e){e.printStackTrace ();} x]hG2on!
} vMX\q
} ~mvv :u
3rZPVR$))
GNwFB)?j
//打印回应的头信息 /EQ^-4yr
public void logResponseHead(HttpURLConnection con) !"/"Mqs3$
{ Zw4%L?
for(int i=1;;i++) pHoxw|'Y
{ FeZWS>N
String header=con.getHeaderFieldKey(i); )#4(4 @R h
if(header!=null) v5 p`=Z@%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (p'/a.bn
Utility.log(header+" : "+con.getHeaderField(header)); Hr]
else FmF[S&gFRs
break; uF3{FYM{I
} -sf[o"T,j
} Jk`l{N
"g"%7jK
/_expSPHl
public void splitterStop() v`'Iew }
{ h(~of(
bStop = true; GU1cMe
} }h/7M
Ap"%%D^{:
@o}J)
} <o|k'Y(-
"5$p=|
L`O7-'`
/* #/9Y}2G|]
**FileAccess.java ? YIe<
*//文件访问(定位，写) bx6=LK
package NetFox; 6W]C`
import java.io.*; h<'tQGC
Kx[+$Qt
zmuRn4Nv
public class FileAccessI implements Serializable{ MYxuQ|w
DuAix)#FN9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pnuwjU-
RandomAccessFile oSavedFile; %0vsm+XQ0E
long nPos; I:al[V2g
.bV^u
*GhV1# <
public FileAccessI() throws IOException FW3E UC)P
{ Xfb-< Q0A
this("",0); i8cmT+}>
} $%&OaAg
RZqMpW
Xa"I
public FileAccessI(String sName,long nPos) throws IOException C[ KMaB
{ &0ymAf5R
oSavedFile = new RandomAccessFile(sName,"rw"); H8@z/
this.nPos = nPos; *U\`HUW
oSavedFile.seek(nPos); +g1+,?cU
} >#T?]5Z'MF
(bNoe(<qU
FL$S_JAw
public synchronized int write(byte[] b,int nStart,int nLen) 1B 0[dK2N
{ n#?y;Y\
int n = -1; #IqRu:csp
try{ V!@6Nv
oSavedFile.write(b,nStart,nLen); FSkX95
n = nLen; VggSDb
} J5f}-W@
catch(IOException e) KxhWZ3
{ UpQda`rb
e.printStackTrace (); cV`NQt<W
} v$;URF%^
a7b1c!
U: <
return n; J*%IvRg
} 3F6A.Ny
%\'G2
l]
} X*Q<REDB
u Vv%k5
G_k_qP^:
/* z-]ND
**SiteInfoBean.java hVZS6gU,x
*/ 7a/ BS(kq<
package NetFox; o~xGE6A*"
d,'gh4C
4] u\5K-
public class SiteInfoBean { jQfnc:'
NSzTl-eS
]R09-s 0$7
private String sSiteURL; //Site's URL 3:OqD~,zy
private String sFilePath; //Saved File's Path ka`}lR
private String sFileName; //Saved File's Name p~(STHDe#
private int nSplitter; //Count of Splited Downloading File `oO*ORq&
Ak}`zIo
-\Z`+kY?p
public SiteInfoBean() Qo(<>d
{//nSplitter的缺省值为5 X VH(zJ
//default value of nSplitter is 5 FId,/la
this("","","",5); NJ$Qm.S
} f&Sovuuh
#z*,-EV|
3^)c5kcI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e+m(g
{ 3Zpq#
sSiteURL= sURL; \mt Y_O
sFilePath = sPath; `Xi)';p
sFileName = sName; ),%@X
this.nSplitter = nSpiltter; mSEX?so=[
LS-_GslE7\
F+D e"^As
} e!k4Ij-]
YQ1rS X3
%r(qQM.Pl
public String getSSiteURL() SapVS*yx@
{ Cs vwc%
return sSiteURL; X7?14W
} -2C^M> HZ
r"VNq&v]9
gla'urb[i|
public void setSSiteURL(String value) iDsY5l
{ G}dq ft5"
sSiteURL = value; &pv*TL8
} \SJX;7ST
3?+t%_[
( ~JtKSq%
public String getSFilePath() XE;'K`%
{ Q} -YD.bx3
return sFilePath; TTo?BVBK
} {yxLL-5c
oy=ej+:
+R8dy
public void setSFilePath(String value) m&MZn2u[4i
{ kFfNDM#D
sFilePath = value; zvv/|z2(r
} x_(K%0+Ca
k~QmDq
A'n7u'6=
public String getSFileName() W$z^U)|t
{ NR^3 1&}It
return sFileName; F*4G@)
} zRR^v&.9K
ki?V eFp
!|J2o8g
public void setSFileName(String value) J!QIMA4{
{ vcP_gJz
sFileName = value; 7VLn$q]:
} |k: FNu]C
Jg.^h1>x
[XP\WG>s
public int getNSplitter() gU@R
{ Iqj?wI1)
return nSplitter; D3+<16[,
} +}f}!h;
h;OHpvk
T!1XL7
public void setNSplitter(int nCount) 1CUI6@Cz)
{ @G|z_
nSplitter = nCount; 8K\S]SZ
} \`*]}48Z
} h~=~csya:
:p$Q3
y XCZs
/* L*{E-m/
**Utility.java Yg;7TKy
*/ ;;432^jD
package NetFox; LS<*5HWX
,jy9\n*<t9
$A98h-*x
public class Utility { k+eeVy
1<0Z@D~F
B2)5Z]
public Utility() <II>io;
{ fV!~SX6S
H00iy$R
QghL=
} H 9?txNea
Jg6@)<n
//线程睡眠 ;"NW=P&
public static void sleep(int nSecond) * YLpC^&
{ d(,M
try{ Z3dI B`@
Thread.sleep(nSecond); c$;Cpt@-j
} byk9"QeY\
catch(Exception e) {@t6[g++
{ '*K%\]
e.printStackTrace (); CI|#,^
} @3?dI@i(
} =vb'T
y*-D
//日志 )jw!,"_4
public static void log(String sMsg) ?oU5H
{ b C"rQJg
System.err.println(sMsg); k!g%vx
} ca'c5*Fs
o"qG'\x
aBKJd
public static void log(int sMsg) [-nPHmZV[
{ G;J!3A;TE
System.err.println(sMsg); TTSq}sb}
} Ge*N%=MX8
} 4B-+DH>{6
Fw%S%*B8g
e#ne5
/* 1@q"rPE^
**TestMethod.java fs,>X!l+
*/ zy8D&7Ytf
package NetFox; EV R>R
|#22pq?RP
bKr73S9
public class TestMethod { 0E^S!A7
~mT([V
X D\;|
public TestMethod() q)RTy|NJ^
{ ///xx/weblogic60b2_win.exe %)y-BdSp.
try{ fLuOxYQbf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Htce<H-P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #D%l;Ae
SiteFileFetch fileFetch = new SiteFileFetch(bean); is{H >#+"
fileFetch.start(); YF)c.Q0
} oox;8d4}y
catch(Exception e){e.printStackTrace ();} TcH7!fUj
YS>VQl
&[[Hfs2:-]
} r@G34QC+
2nI^fVR%\
uh3<%9#\k
public static void main(String[] args) H `_{n<
{ 5Qxm\?0J
new TestMethod(); VW**N}1#C
} @.h;k4TD
} PLK;y
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