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)); )Co&(;zf
} 1.6Y=Mh=i[
for(int i=0;i<nEndPos.length-1;i++) z pV+W-j]
{ JA(M'&q4
nEndPos = nStartPos[i+1]; k}tTl 2
} "H"4]m1Wc
nEndPos[nEndPos.length-1] = nFileLength; oy< q;'
} zhW.0:9 CR
} DI,8y"!5
!c#~g0H+
A!n)Fpk
//启动子线程 S#g=;hD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g]a5%8*{
for(int i=0;i<nStartPos.length;i++) iF!r}fUU6
{ >?yxig:_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 U!-Zn!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *B ]5K{N
nStartPos,nEndPos,i); s>+,u7EV
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >||=#;
fileSplitterFetch.start(); \ W.uV[\
} DuzJQSv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FXd><#U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i<>zN^zn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p^/6Rb"e
nEndPos = " + nFileLength); #lo1GoL\
// fileSplitterFetch[nPos.length-1].start(); 8H<:?D/tH
Zwm2T3@e
[L4s.l_#
//等待子线程结束 |WMP_sGn
//int count = 0; `Ir{ax&H.e
//是否结束while循环 sPoH12?AL
boolean breakWhile = false; =bDy :yY}
}2CVA.Qm!
?Gr2@,jlD
while(!bStop) 6Q}WX[| tQ
{ k6|wiSyu
write_nPos(); =U)e_q
Utility.sleep(500); 2F- ]0kGR|
breakWhile = true; ^9wQl!e ob
J3P)oM[
rM5{R}+;
for(int i=0;i<nStartPos.length;i++) /_g-w93
{ [flx/E
if(!fileSplitterFetch.bDownOver) ;wF 0s
{ ~o?(O1QY
breakWhile = false; a3?D@@Qnw
break; 8e{S(FZ7Ed
} ~wl4
} mYRW/8+g
if(breakWhile) a ]~Yi.H
break; p;k7\7
fRT4,;
0Xx&Z8E
//count++; KMo]J1o
//if(count>4) kH9P(`;Vq
// siteStop(); .*_uXQ
} O>)Fl42IeD
p.50BcDg
SuuLB6{u3
System.err.println("文件下载结束！"); d>OLnG> F
} jXCSD@?]K
catch(Exception e){e.printStackTrace ();} {=)g?!zC
} :,]*~Nl
D<SLv,Y
CQGq}.Jt!
//获得文件长度 z&x3":@u<
public long getFileSize() =FfxHo1k
{ *W&}}iL
int nFileLength = -1; {!G
try{ Aq~}<qkIF+
URL url = new URL(siteInfoBean.getSSiteURL()); WPnw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ay-M.J
httpConnection.setRequestProperty("User-Agent","NetFox"); Rz\:)<G
{~u#.(
)CAEqP
int responseCode=httpConnection.getResponseCode(); Z&w/JP?
if(responseCode>=400) Yfotq9.=+
{ Jq8CII
processErrorCode(responseCode); $MPh\T
return -2; //-2 represent access is error tITx+i
} @_ Q
+^0Q~>=VD
Mb0l*'ZF
String sHeader; YrRD3P.P
BZr$x8%ki
Q(gc(bJV
for(int i=1;;i++) k.MAX8
{ MfJ8+3@K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); npD`9ff
//Utility.log(in.readLine()); ,KO_h{mI<
sHeader=httpConnection.getHeaderFieldKey(i); +&j&es
if(sHeader!=null) wEu"X
{ vSf ?o\O
if(sHeader.equals("Content-Length")) fVJsVZ"6v`
{ zVL"$ )
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `Fn6*_n
break; #Y9'n0 AL
} qT}AY.O%^
} ZA>p~Zt
else h'D-e5i
break; RD1N@sHDKc
} o fw0_)!Q
} 93+p~?
catch(IOException e){e.printStackTrace ();} ;3 |Z}P
catch(Exception e){e.printStackTrace ();} "B9aJo
_pM~v>~*+
3\~ RWoB0u
Utility.log(nFileLength); bU+ z(Eg6
1_Ag:>#X
U!xOJ
return nFileLength; nS`DI92I
} 0w24lVR.
E?@batIrf
RXZ}aX[h
//保存下载信息（文件指针位置） n:i?4'-}
private void write_nPos() ?oKY"C8/
{ h_{//W[
try{ nm3/-Q},
output = new DataOutputStream(new FileOutputStream(tmpFile)); xdqiogue
output.writeInt(nStartPos.length); D%k`udz<
for(int i=0;i<nStartPos.length;i++) ?~g X7{>
{ ]EhU8bZ
// output.writeLong(nPos); (w+dB8)X
output.writeLong(fileSplitterFetch.nStartPos); kCoTz"Z-
output.writeLong(fileSplitterFetch.nEndPos); N4z(2.
} %M/rpEE"b%
output.close(); UCv9G/$
} XX@@tzN
catch(IOException e){e.printStackTrace ();} EoOB0zo}Y+
catch(Exception e){e.printStackTrace ();} `fA|])3T
} D. _*p
iCK p"(kf
>AsrPU[
//读取保存的下载信息（文件指针位置） Z[&7NJo(
private void read_nPos() ,m^@S
{ w)u6J,
try{ D-GIrw{>5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `z?6.+C
int nCount = input.readInt(); y66V&#`,e0
nStartPos = new long[nCount]; F_ Cp,
nEndPos = new long[nCount]; FN)vFQ#J
for(int i=0;i<nStartPos.length;i++) kq m$a
{ /!//i^
nStartPos = input.readLong(); 7j <:hF~
nEndPos = input.readLong(); k;AV'r
} v]tNJ=aI
input.close(); !VF.=\iH/
} Le*sLuxk<
catch(IOException e){e.printStackTrace ();} E}*
catch(Exception e){e.printStackTrace ();} j!oD9&W4~
} k8~/lE.Wy
H$j`75#u?-
SW^/\cJ^
private void processErrorCode(int nErrorCode) 5NT?A,r"
{ HRPNZ!B
System.err.println("Error Code : " + nErrorCode); GdxMHnn=
} "AAzBWd/
.gPXW=r
XKTX~:
//停止文件下载 mnwYv..ePz
public void siteStop() LZ"yMnhOf
{ >>'t7U##
bStop = true; 3Xun>ZQ-
for(int i=0;i<nStartPos.length;i++) q')MKR*
fileSplitterFetch.splitterStop(); jZ;dY~fE
-wqnmK+G
m3La;%aA0
} T==(Pw7R7
} rTR4j>Ua~
//负责部分文件的抓取 Ai 9UB=[R
**FileSplitterFetch.java [^U#ic>cT
*/ %kcyE<c
package NetFox; D)u 9Y
>*5+{~k~4
<`~zKFUQ[
import java.io.*; ylEQeN
import java.net.*; 0%9Nf!j
iyRB}[y
_B5t)7I
public class FileSplitterFetch extends Thread { AxXFzMW
:Y{aa1
N0D)d
String sURL; //File URL <}^W9>u<
long nStartPos; //File Snippet Start Position FzDZ<dJ
long nEndPos; //File Snippet End Position *i}Nb*Z3
int nThreadID; //Thread's ID D9#?l<D
boolean bDownOver = false; //Downing is over z&"-%l.b@}
boolean bStop = false; //Stop identical u)DhkF|
FileAccessI fileAccessI = null; //File Access interface #\Q{?F!4
'_~X(izc
KvFGwq"X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UP@a ?w
{ sw(dd01a 7
this.sURL = sURL; E>BP b
this.nStartPos = nStart; qrFC4\q}
this.nEndPos = nEnd; b :Knc$
nThreadID = id; $7#N@7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q 16jL,i
} a!;]9}u7
=s2dD3Fr|
t5%\`Yo?
public void run() HlkG^:)
{ 2^Tj@P7
while(nStartPos < nEndPos && !bStop) rb/m;8v>
{ 0]F'k8yLN
C3Hq&TVf/
:?Xd&u0){
try{ 5 W<\J
URL url = new URL(sURL); 7VF^&6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \~(ww3e
httpConnection.setRequestProperty("User-Agent","NetFox"); H?dmNwkPY
String sProperty = "bytes="+nStartPos+"-"; PgKA>50a
httpConnection.setRequestProperty("RANGE",sProperty); 1I?D$I>CV
Utility.log(sProperty); Wp0e?bK_
Z=ayVsJ3
5aF03+ko
InputStream input = httpConnection.getInputStream(); ,1\nd{
//logResponseHead(httpConnection); `Z3Qx~fx
CvCk#:@HM
hrwQh2sm
byte[] b = new byte[1024]; YU89m7cc'
int nRead; ZWC-<QO"<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6,"fH{Bd
{ ^lqcF.
nStartPos += fileAccessI.write(b,0,nRead); AxaabS$\
//if(nThreadID == 1) Pez 7HKW:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TK)Kq
} iY=M67V
4T-9F
>H@ zP8
Utility.log("Thread " + nThreadID + " is over!"); %!r>]M <
bDownOver = true; #?xhfSgr
//nPos = fileAccessI.write (b,0,nRead); RLypWjMx$
} FuOP+r!H
catch(Exception e){e.printStackTrace ();} KzQ\A!qG
} _YXk,ME!Q
} ?|8QL9Q"|
dOm#NSJVd
f`5e0;zm
//打印回应的头信息 uzO%+B!
public void logResponseHead(HttpURLConnection con) iOB]72dh
{ }+[H~8)5
for(int i=1;;i++) y.AF90Q>)
{ UFxQ-GV4
String header=con.getHeaderFieldKey(i); m6aq_u{W
if(header!=null) +\FTR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5!ll #/ {`
Utility.log(header+" : "+con.getHeaderField(header)); /B$"fxFf
else Y[AL!h
break; Hno:"k?
} mPNT*pAO
} 10v4k<xb
6V=69}
Q 'R@'W9
public void splitterStop() })OgsBk
{ `}1IQ.3
bStop = true; B2~KkMF
} r5qp[Ss3F
NymS8hxR
=J0X{Ovn4z
} )bZS0f-
esH>NH_
'CT8vt;
/* ^l#Z*0@><~
**FileAccess.java #vi `2F
*//文件访问(定位，写) RVv@x5
package NetFox; TIg3'au
import java.io.*; od{b]HvgS
y]5O45E0
8(UUc>g
public class FileAccessI implements Serializable{ ylF%6!V}4V
':8yp|A|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >Vr+\c
RandomAccessFile oSavedFile; zbdmz
long nPos; Z(p kj
}EmNSs`$r
6P=6E
public FileAccessI() throws IOException VLW<"7I 6\
{ 0c4H2RW
this("",0); _tZT
} WL4{_X
f&glY`s#
`;-K/)/x
public FileAccessI(String sName,long nPos) throws IOException 7aVQp3<
{ 1hj']#vBu
oSavedFile = new RandomAccessFile(sName,"rw"); 4I7}
this.nPos = nPos; >HatbbA
oSavedFile.seek(nPos); &MnS( 82L
} >3V{I'^^-
$:V'+s4o
^)Xl7d|m+
public synchronized int write(byte[] b,int nStart,int nLen) [z$th
{ OD!b*Iy|
int n = -1; 4y&%YLMpl
try{ !T/^zc;G
oSavedFile.write(b,nStart,nLen); 6q ._8%
n = nLen; ${^WM}N
} yTWP1
catch(IOException e) )Xxu-/-
{ !6:kJL}U
e.printStackTrace (); GU'/-6-T
} 4S>A}rWz
_p/ _t76s
V|3}~(5=
return n; !6hUTjhW7z
} _,:gSDW|
( /{Wu:e
hER]%)#r
} ,$ L>
I/D(gY06<
H(U`S
/* 4(>|f_$
**SiteInfoBean.java K^j7T[pR
*/ \EF^Ag
package NetFox; s(W]>Ib
'+LbFGrO3
ca/AScL
public class SiteInfoBean { Jylav:
T)J=lw
!L4Vz7C
private String sSiteURL; //Site's URL [F4]pR(
private String sFilePath; //Saved File's Path XnmQp)nyV
private String sFileName; //Saved File's Name m[6?v;w
private int nSplitter; //Count of Splited Downloading File S%zn {1F
T9.3
Q[EpE,
public SiteInfoBean() c8!q_H~
{//nSplitter的缺省值为5 T:&
//default value of nSplitter is 5 {/SUfXq
this("","","",5); 5[3vup?
} a"gZw9m@
WPT0=Hqp7
'E FP/(2J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >5Y%4++(
{ k@MAi*
sSiteURL= sURL; C&Rv$<qc
sFilePath = sPath; T$[50~
sFileName = sName; ^]}+s(
this.nSplitter = nSpiltter; T.\=R
;oW#>!HrY
*@`Sx'5!
} Fd!Np7xw
'jAX&7G`
qKu/~0a/
public String getSSiteURL() JB.f7-
{ M?mPi 3
return sSiteURL; .YYfba#{
} ,@1rP55
ZoJ_I >uv
J:g4ES-/
public void setSSiteURL(String value) ~JhH ,E
{ ASA ]7qyO
sSiteURL = value; F uYjrzmx
} OolYQU1_
Aw#@}TGT
c'#w 8V
public String getSFilePath() }ZaZPB/_}P
{ /dGpac
return sFilePath; QP HibPP:
} 1.29%O8V_
L-. +yNX)
u7 s-
public void setSFilePath(String value) />^sGB
{ GHeucG}?
sFilePath = value; <k59Ni9
} )Iu0MN&
/G*]3=cSe
"m2g"xa\7
public String getSFileName() ?r P'PUB
{ +d/V^ <#
return sFileName; H!N`hEEj>
} m5i?<Ko@
YU>NGC]}d
KV&4Ep#
public void setSFileName(String value) 7dxTyn=
{ PydU.,^7
sFileName = value; ]J|]IPXy
} G,o5JL"t
z)AZ:^!O
LC8&},iu
public int getNSplitter() 4WspPHj
{ 1nGpW$Gx
return nSplitter; 2h=QJgpCG
} n:dnBwY
f%#q}vK-
'P'f`;'_DC
public void setNSplitter(int nCount) ":igYh
{ ,u.G6"<
nSplitter = nCount; vGX L'k
} M/?*?B
} vca]yK<u
b{ M'aV
$W_sIS0\z
/* OoIs'S-Z#
**Utility.java 4$W}6v
*/ (AIgW
package NetFox; c+a"sx\
yyZs[5Q
5N~JRq\
public class Utility { 'tJb(X!]q
=[_=y=G
qS|ns'[
public Utility() UO~Xzx!e
{ /9QC$Z):<
pc+'/~
,M?K3lG\g[
} *OM+d$l!
G!<-9HA5
//线程睡眠 Sm5T/&z
public static void sleep(int nSecond) BQo$c~
{ b+/z,c6w
try{ AQ)DiH
Thread.sleep(nSecond); 1\u{1 V
} Z@1vJH6IbA
catch(Exception e) 2=]Xe#5J=
{ [H4)p ,R
e.printStackTrace (); _GW,9s^A
} 'lWgHmE
} #ULjK*)R
$R&K-;D/8
//日志 v?O6|0#x
public static void log(String sMsg) k`(Cwp{Oc
{ Kry^47"
System.err.println(sMsg); L9}%tEP
} B'}pZOa[Wb
xq@_' 3X
/:GeXDJw
public static void log(int sMsg) A6S|pO1)3
{ 4NK{RN3
System.err.println(sMsg); ]8o[&50y
} <FofRFaS
} 5fDp"-
'UFPQ
XF Cwa
/* 9%iv?/o*L
**TestMethod.java aGs\zCAP
*/ (dnaT-M3
package NetFox; 7*>(C*q=
=yCz!vc
q]\GBRp
public class TestMethod { Nc_Qd4<[@G
v/G)E_
BenUyv1d
public TestMethod() o |"iW" +
{ ///xx/weblogic60b2_win.exe 2t}^8
try{ P.Gmj;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g;-6Hg'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I&Z+FL&@f
SiteFileFetch fileFetch = new SiteFileFetch(bean); OhW o
fileFetch.start(); S2PPwCU
} f+V^q4
catch(Exception e){e.printStackTrace ();} /oC@:7
LUKt!I0l
L43]0k
} `)n/J+g
p%#=OtkC
ZxoAf;U~
public static void main(String[] args) AYHefAF<w
{ J`'wprSBb
new TestMethod(); h=o%\F4
} p/ au.mc
} Mh"vH0\Lj
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