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)); ])'22sY
} vi["G7
for(int i=0;i<nEndPos.length-1;i++) .AH#D}m
{ HZ5*PXg~
nEndPos = nStartPos[i+1]; q El:2<
} X2(TuR*t
nEndPos[nEndPos.length-1] = nFileLength; A&~G
} i*#Gq6qZq
} Eh#W*Bg
!F/;WjHz
YU9xANi6
//启动子线程 (WCpaC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1&ZG6#16q
for(int i=0;i<nStartPos.length;i++) qS*qHT(u19
{ 9(QY~F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \'&:6\-fw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HtgVD~[]
nStartPos,nEndPos,i); 8TD:~ee
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;iy]mPd
fileSplitterFetch.start(); 73A1+2
} /P<RYA~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %L=roqz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _' Xt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R4 ;^R
nEndPos = " + nFileLength); u^s{r`/
// fileSplitterFetch[nPos.length-1].start(); =&U JFu
v2gK(&?
e!d& #ofw|
//等待子线程结束 p )etl5
//int count = 0; ba1zu|@w
//是否结束while循环 ah>;wW!6/
boolean breakWhile = false; KVvIo1$N
MScjq
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while(!bStop) eY"y[
{ *Tl"~)'t~
write_nPos(); -d[9mS
Utility.sleep(500); RvZi%)
breakWhile = true; K%[Rv#>;q|
b&"=W9(V
BLgmFE2
for(int i=0;i<nStartPos.length;i++) Y 6K<e:Y
{ B%6>2S=E
if(!fileSplitterFetch.bDownOver) 1?]Gl+}
{ w{?nX6a@p
breakWhile = false; Yn+/yz5k_
break; X<Rh-1$8F
} 4};iL)
} Y\(Q
if(breakWhile) q{n~v>wU
break; |fYNkD8z1
w1KLQd:yq
z2i?7)(?;A
//count++; cR 4xy26s
//if(count>4) R;.zS^LL
// siteStop(); w{#K.dx
} kpsus \T
@OZW1p
p~J`}>yo
System.err.println("文件下载结束！"); e-sMU
} C8}ujC
catch(Exception e){e.printStackTrace ();} dB ?+-aE
} IxAKIa[HY
;+>-uPT/1
oJ ,t]e*q=
//获得文件长度 BEPeK
public long getFileSize() ;Z-xum{
{ \m1r(*Ar
int nFileLength = -1; lsCD%P
try{ wA|m/SZx
URL url = new URL(siteInfoBean.getSSiteURL()); *>n<7T0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~P 1(%FZ
httpConnection.setRequestProperty("User-Agent","NetFox"); K||9m+
^&am]W;T
^*#5iT8/
int responseCode=httpConnection.getResponseCode(); tj;<Z.
if(responseCode>=400) NC)Iu
{ TFb9gOTJ
processErrorCode(responseCode); +yiGZV/X
return -2; //-2 represent access is error rBye%rQRq
} 1/c7((]7(,
'IY?7+[
<_=a1x
String sHeader; P#\L6EO.
d^ L`dot
r"x|]nvg^
for(int i=1;;i++) 0V`s 3,k
{ +e);lS"+/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /zMiy?
//Utility.log(in.readLine()); mk~&>\
sHeader=httpConnection.getHeaderFieldKey(i); G4{ zt3{
if(sHeader!=null) PCF!Y(l
{ B4bC6$Lg
if(sHeader.equals("Content-Length")) Bf~
{ U=\ZeYK.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x[U/ 8#f&
break; G&)A7WaC
} H{ p
} &%+}bt5
else T~J6(,"
break; GKu@8Ol-wu
} Z@>hN%{d+g
} -'QvUHL|
catch(IOException e){e.printStackTrace ();} Ac0C,*|^
catch(Exception e){e.printStackTrace ();} !FX0Nx=oi
1q]V/V}
5, R\tJCK
Utility.log(nFileLength); }]$%aMxy T
AWsO?|YT
qX^#fk7]
return nFileLength; }26?bd@e`
} \`}Rdr!p%
v!27q*;8H
7tP?([o%F
//保存下载信息（文件指针位置） RMUR@o5N
private void write_nPos() i 2hP4<;h
{ J3KY?,g3O_
try{ YHAhF@&
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5+].$
output.writeInt(nStartPos.length); |6'(yn
for(int i=0;i<nStartPos.length;i++) ?lW-NPr
{ K:gxGRE
// output.writeLong(nPos); srXGe`VL
output.writeLong(fileSplitterFetch.nStartPos); .Qm"iOyM
output.writeLong(fileSplitterFetch.nEndPos); 5+\[x`
} eu@hmR8T
output.close(); |s`j=<rNQI
} }u:@:}8K
catch(IOException e){e.printStackTrace ();} <^snS,06
catch(Exception e){e.printStackTrace ();} \W=~@k
} ivYHq#b59
wvBx]$SC
CE]0OY
//读取保存的下载信息（文件指针位置） 6My=GByC
private void read_nPos() xy)Y)yp
{ u&yAMWl
try{ 43-mv1>.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PeGA+0bm
int nCount = input.readInt(); 92!1I$zi
nStartPos = new long[nCount]; f2ygN6(>
nEndPos = new long[nCount]; 6SI`c+'@5
for(int i=0;i<nStartPos.length;i++) {XH!`\
{ va F^[/ (g
nStartPos = input.readLong(); =Ryh@X&
nEndPos = input.readLong(); M]4qS('[
} S&_Z,mT./
input.close(); `T7gfb%1-3
} 4Xi _[ Xf
catch(IOException e){e.printStackTrace ();} Wew'bj
catch(Exception e){e.printStackTrace ();} & 9}L +/,
} ^ZV1Ev8T6
(7^5jo[D
f1w&D ]|S+
private void processErrorCode(int nErrorCode) rOQ@(aUAZ
{ *@/1]W
System.err.println("Error Code : " + nErrorCode); WP[h@#7<
} nt.A X
&?UIe]
-x)Oo`
//停止文件下载 Xu\FcQ{
public void siteStop() 12qX[39/
{ BwMi@r =
bStop = true; s\2t|d
for(int i=0;i<nStartPos.length;i++) T9w;4XF
fileSplitterFetch.splitterStop(); eH,r%r,
{JTO Q 8&
.|W0B+Z8
} &x6Z=|Ers
} >a/]8A
//负责部分文件的抓取 ~R^~?Y%+<
**FileSplitterFetch.java tmT/4Ia
*/ C#{s[l\]
package NetFox; HwfBbWHr'
1bjhEOW
"P.H
import java.io.*; Jm8{@D%
import java.net.*; 8CCd6)cG
]."~)
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public class FileSplitterFetch extends Thread { F]o&m::/K
SNqw2f5
[ u7p:?WDW
String sURL; //File URL F/,K8<|r>
long nStartPos; //File Snippet Start Position 4)MKYhm
long nEndPos; //File Snippet End Position xPMTmx?2
int nThreadID; //Thread's ID v0uDL7
boolean bDownOver = false; //Downing is over -OV:y],-
boolean bStop = false; //Stop identical 6[3oOO:uo
FileAccessI fileAccessI = null; //File Access interface ?pSb,kN}'
1./uJB/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p1~u5BE7O
{ 2kMBe%
this.sURL = sURL; z}?*1c
this.nStartPos = nStart; L&h@`NPO a
this.nEndPos = nEnd; PNy)TqdRS
nThreadID = id; <ua`WRQr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @CGci lS=
} dJyf.VJ
X*f#S:kiNU
6zv-nMZc
public void run() 6&,n\EXF
{ me-Tv7WL
while(nStartPos < nEndPos && !bStop) 1^&qlnqH
{ A"|y<
l Ozi|
Rdb[{Ruxb
try{ @o4+MQFn
URL url = new URL(sURL); w7Fz(`\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uu0"k<Tp
httpConnection.setRequestProperty("User-Agent","NetFox"); Pnf|9?~$H
String sProperty = "bytes="+nStartPos+"-"; udw>{3>
httpConnection.setRequestProperty("RANGE",sProperty); G bW1Lq&"
Utility.log(sProperty); t~_j+k0K#
`zf,$67>1
+,oEcCi
InputStream input = httpConnection.getInputStream(); wxC&KrRF
//logResponseHead(httpConnection); n1 k2<BU4b
K>%}m,
'+?L/|'
byte[] b = new byte[1024]; $glt%a
int nRead; 2AYV9egZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ek'~i
{ |5J'`1W
nStartPos += fileAccessI.write(b,0,nRead); GxH]
//if(nThreadID == 1) KmF"Ccc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k55s-%Ayr
} ^eF%4DUC;
VN3"$@-POK
bUv}({
Utility.log("Thread " + nThreadID + " is over!"); Z8vMVo
bDownOver = true; </xz V<Pi
//nPos = fileAccessI.write (b,0,nRead); K|n%8hRy
} #fB&Hv #s7
catch(Exception e){e.printStackTrace ();} U(xN}Y?
} 8w,+Y]X<P[
} 9Yu63s ia
~!V5Ug_2
qW~Z#Si
//打印回应的头信息 >WYiOXYv
public void logResponseHead(HttpURLConnection con) 1P8XVI'
{ ^a>3U l{
for(int i=1;;i++) PhUG}94
{ 0`WjM2So
String header=con.getHeaderFieldKey(i); tO?NbWcp
if(header!=null) fEv`iXZG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 31VDlcnE
Utility.log(header+" : "+con.getHeaderField(header)); tW^oa
else gu1:%raXd
break; 4lM)ZDg
} .qd/ft2
} c:*[HO\
[ADSGnw
9_=0:GHk
public void splitterStop() k4n4BL
{ CBkI! In2
bStop = true; cj[a^ ZH
} EN,PI~~F
c >O>|*I
kdgU1T@y.
} g4eEkG`XTS
5{zmuv:
\C{Dui)F
/* 7dm:L'0
**FileAccess.java H[WsHq;T+9
*//文件访问(定位，写) c[IT?6J4
package NetFox; `s )- lI
import java.io.*; |2L|Zp&
o"kVA;5<G
E{wnhsl{
public class FileAccessI implements Serializable{ sn!E$ls3O
Q1 t-Z;X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @p$Nw.{'
RandomAccessFile oSavedFile; 61aU~w11a
long nPos; XBr-UjQ
c*m7'\
mp'Z.4
public FileAccessI() throws IOException Yg<L pjq5X
{ Ri
this("",0); #oYPe:8|m
} 6D\$K
bHKTCPf
$yn7XonS
public FileAccessI(String sName,long nPos) throws IOException (yJY/|
{ U}yq*$N
oSavedFile = new RandomAccessFile(sName,"rw"); e7_.Xr~[
this.nPos = nPos; u# TNW.
oSavedFile.seek(nPos); '9ki~jtf=
} a<NZC
W>E/LBpE4
+!~"ooQZh
public synchronized int write(byte[] b,int nStart,int nLen) K]{x0A
{ @%^JB
int n = -1; #NyfE|MKBC
try{ DXa!"ZU
oSavedFile.write(b,nStart,nLen); i-jrF6&
n = nLen; ,<CFjtelO
} 6*aU^#Hz6
catch(IOException e) SzTa[tJ+
{ 2FVO@D
e.printStackTrace (); "y9]>9:$-
} X7~^D[X
hEh` cBO
%&5PZmnW
return n; /g]NC?
} K\trT!I
3 0.&Lzz
6"L,#aKm^
} "*bP @W
/ucS*m:<x
#FhgKwx
/* PY@BgL=/
**SiteInfoBean.java Dq~\U&U\$
*/ '% if< /
package NetFox; /prR;'ks
w7%.EA{N
<-h[I&."
public class SiteInfoBean { {y%|Io`P
'>^!a!<G
!jTxMf
private String sSiteURL; //Site's URL h}U>K4BJ
private String sFilePath; //Saved File's Path Wt M1nnJp
private String sFileName; //Saved File's Name hh[@q*C
private int nSplitter; //Count of Splited Downloading File @kPe/j/[1
fq[1|Q
1xD?cA\vu
public SiteInfoBean() K%g_e*"$
{//nSplitter的缺省值为5 Yh["IhjR
//default value of nSplitter is 5 jX;$g>P
this("","","",5); 4c]=kbGW
} ( }RJW:
1wg#4h43l
u- }@^Y$M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bfu/w
{ VvUP;o&/
sSiteURL= sURL; zN&m-nrw
sFilePath = sPath; <'N~|B/yZ
sFileName = sName; N[zR%(YS
this.nSplitter = nSpiltter; o}=c(u
8xb({e4
0B]c`$"aD
} rNoCmNm
?dyt!>C
4[ *G
public String getSSiteURL() 9 >"}||))
{ MAcjWb~f
return sSiteURL; ~='}(Fg:
} v[\Z^pccgj
XE$;Z'Qhjm
%%T?LRv
public void setSSiteURL(String value) C*stj
{ ^Z+p_;J$p
sSiteURL = value; w y&yK*w
} GOUO
" V4@nv
N5b^
public String getSFilePath() 'x,6t66*"l
{ v[\GhVb
return sFilePath; {yFMY?6rf
} ^8=e8O
*pYawT
0O?\0k;o
public void setSFilePath(String value) yS.)l
{ C'6c,
sFilePath = value; e8 c.&j3m
} bHg 0,N
p:ubj'(U05
2i$_ ,[fi
public String getSFileName() ZfibHivz
{ pN{XGkX.
return sFileName; ]$!7;P
} w:9M6+mM^
lE8(BWzw
z .+J\
public void setSFileName(String value) #G\Ae:O
{ a/n~#5-
sFileName = value; ETm:KbS
} ~g}blv0q+B
lXRB"z
MM*9Q`cB
public int getNSplitter() E <N%
{ T>irW(
return nSplitter; cv_t2m
} : cPV08i
W/.n R[!
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public void setNSplitter(int nCount) J4Ca0Ag
{ m A('MS2
nSplitter = nCount; blUS6"kV}
} 3uL$+F
} epI~w
ddY-F }z~
$S^rKp#
/* LhSXz>AX
**Utility.java c~={A
*/ w{riXOjS4
package NetFox; k- exqM2x=
c_u7O \
=N2@H5+7
public class Utility { 1U(!%},
cR/e Zfl
Gh}* <X;N
public Utility() hyY^$p+
{ :BF WX
_TyQC1 d
iV:\,<8d
} AD>/#Ul
9hgIQl
//线程睡眠 1[-RIN;U8
public static void sleep(int nSecond) f[q_eY
{ gX(8V*os^
try{ x[R?hS,0t
Thread.sleep(nSecond); X;v{,P=J
} MfraTUxIo/
catch(Exception e) 212 =+k
{ X7SSTcA
e.printStackTrace (); 88}04
} b/4gs62{k
} N6v*X+4JH
O]l-4X#8F
//日志 uN0'n}c;1.
public static void log(String sMsg) ~Fo`Pr_
{ @"iNjqxh
System.err.println(sMsg); z'zC
} r#d]"3tH
f5R%F~
[-\DC*6
public static void log(int sMsg) jRp @-S#V
{ ]0pI6"
System.err.println(sMsg); DvTbt?i[
} aqwW`\
} Lve$H(GHT
BbI),iP
S;BMM8U
/* nb@<UbabW}
**TestMethod.java ZRUAw,T*
*/ 4VzSqb
package NetFox; tfv@ )9
fVq,?
XX*f
public class TestMethod { 0qBXL;sE
x!onan
M<@9di7c
public TestMethod() r?x~`C
{ ///xx/weblogic60b2_win.exe z=LO$,JW`
try{ /Wy9".
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (; Zl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5;9.&f
SiteFileFetch fileFetch = new SiteFileFetch(bean); iz-O~T/^
fileFetch.start(); )Y?E$=M+B
} ;8gODj:dO
catch(Exception e){e.printStackTrace ();} b{W ,wn
7.C]ZcU
^Cg@'R9
} NmN:x&/
6uFGq)4p@
&HJ~\6r\
public static void main(String[] args) JM*rPzp
{ *JaFt@ x
new TestMethod(); C,u;l~zz
} .|K\1qGW0
} \)PS&Y8n
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