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)); e;LC\*dG
} gQ|?~hYYv
for(int i=0;i<nEndPos.length-1;i++) ?kRx;S+
{ tOZ-]>U
nEndPos = nStartPos[i+1]; P)~olrf
} sn Ou
nEndPos[nEndPos.length-1] = nFileLength; LMN`<R(q]
} YRv}w3yQ
} QWWI
crx%;R
N/1xc1$SB
//启动子线程 jthyZZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V2:S 9vO'
for(int i=0;i<nStartPos.length;i++) :G=ol2Q
{ m 0Uu2Z4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p^Z|$aZZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [.$/o}
nStartPos,nEndPos,i); p9!jM\(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ')iyD5/4
fileSplitterFetch.start(); ?;Da%VS3
} I]cZcx,<q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l[<o t9P[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l*Fp}d.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rT[b ^l}
nEndPos = " + nFileLength); =B`=f,,#3
// fileSplitterFetch[nPos.length-1].start(); P057]cAat<
;y)3/46S
FuAs$;
//等待子线程结束 K;`W4:,
//int count = 0; -zZb]8\E
//是否结束while循环 x]608I T
boolean breakWhile = false; 5 o[E8c8
Zeq^dV5y77
\Hq=_}]F
while(!bStop) ^* CKx
{ p S|
write_nPos(); Mp^G7JY,
Utility.sleep(500); kX*.BZI}C
breakWhile = true; k9&W0$I#
.3>q3sS
e:.D^GFi
for(int i=0;i<nStartPos.length;i++) WopA7J,
{ Q91mCP~$
if(!fileSplitterFetch.bDownOver) 9)n3f^,Oj*
{ QVmJ_WT
breakWhile = false; 8hMy$
break; 'oM=ZU8wo
} Wd7qpWItjQ
} X@/wsW(kM\
if(breakWhile) &#9HV
break; )Ofwfypc
DZ:$p.
+S1h~@c:B
//count++; \_)mWK,h
//if(count>4) p77=~s
// siteStop(); '*`1uomeo
} Z4{N|h?
T:!H^
j#l1KO^y
System.err.println("文件下载结束！"); fF5\\_,
} "y ;0}9]n1
catch(Exception e){e.printStackTrace ();} jS|jPk|I.
} XAB/S8e
7{VN27Fa_
_Om5wp=:
//获得文件长度 P` Gb}]rW
public long getFileSize() 0OnqKgf
{ }_Y\6fcd
int nFileLength = -1; a,:Nlr3
try{ Sg(\+j=
URL url = new URL(siteInfoBean.getSSiteURL()); _+Uf5,.5yU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eMP0BS"
httpConnection.setRequestProperty("User-Agent","NetFox"); Bi0&F1ZC!
vCtnjWGX}/
mAe)Hy %
int responseCode=httpConnection.getResponseCode(); 1R]h>'
if(responseCode>=400) q1A0-W#4
{ "rrE_
processErrorCode(responseCode); hy3?.
return -2; //-2 represent access is error I@1VX5
} :Yi 4Ia
H.O&seY
}To-c'
String sHeader; <[17&F0
!3"Hn
dAaxbP|
for(int i=1;;i++) uK[gI6M
{ JaN53,&<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7+$P6[*
//Utility.log(in.readLine()); n]K{-C;
sHeader=httpConnection.getHeaderFieldKey(i); "&\]1A}Z-x
if(sHeader!=null) {!pYQ|#
{ x139Ckn
if(sHeader.equals("Content-Length")) #BIY[{!
{ NRs%q}lX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SPINV.
break; cdg&)
} b\xse2#
} b^<7@tY
else J& D0,cuk
break; Nu><r
} iUS?xKN$~-
} F[X;A\
catch(IOException e){e.printStackTrace ();} rWp+kV[Ec>
catch(Exception e){e.printStackTrace ();} hM8FN
I.1(qbPkF+
CSr2\ogT
Utility.log(nFileLength); 0}\8,U
k[1w] l8
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return nFileLength; n&E/{o(
} eM^Y
[t]q#+Zs
n%{oFTLCo
//保存下载信息（文件指针位置） *#B"%;Ln
private void write_nPos() V|;os
{ >UV=k :Q
try{ B\>3[_n
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0fa8.g#I$
output.writeInt(nStartPos.length); vARZwIu^D
for(int i=0;i<nStartPos.length;i++) :]`JcJ
{ ho6,&Bp8
// output.writeLong(nPos); k-$J #
output.writeLong(fileSplitterFetch.nStartPos); _D1)_?`a@-
output.writeLong(fileSplitterFetch.nEndPos); oXGP6#
} ,"T[#A~
output.close(); 02po;
} 9}11>X
catch(IOException e){e.printStackTrace ();} 6/|"y
catch(Exception e){e.printStackTrace ();} ]iaQD _'\
} ,u
>yr3C
.X6V>e)(3
//读取保存的下载信息（文件指针位置） 4Gsq)i17j
private void read_nPos() S{~j5tQv^q
{ lp5b&I_
try{ P}D5 j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sV`XJ9e|
int nCount = input.readInt(); Aoy=gK
nStartPos = new long[nCount]; <##aD3)
nEndPos = new long[nCount]; w6[$vib'
for(int i=0;i<nStartPos.length;i++) o q cu<]
{ ?$4CgN-
nStartPos = input.readLong(); \6,Z<.I
nEndPos = input.readLong(); /O$)m[
} SqT+rvTh
input.close(); fXAD~7T*s
} #s-li b
catch(IOException e){e.printStackTrace ();} ''CowI
catch(Exception e){e.printStackTrace ();} QtfLJ5vi
} PML84*K -
= 8\'AU
N<|-b0#Z6
private void processErrorCode(int nErrorCode) mCEWp
{ [&{NgUgu"
System.err.println("Error Code : " + nErrorCode); 21\?FQrz
} )H1chNI)
x_x|D|@wM
9q"G g?
//停止文件下载 h>"Z=y
public void siteStop() cP8@'l@!
{ Ky'\t7p u
bStop = true; 1)!]zV
for(int i=0;i<nStartPos.length;i++) ,+RoJwi m
fileSplitterFetch.splitterStop(); L9 H.DNA
_2Fa.gi
f2{qj5 K
} W7 9.,#
} Bqb3[^;~
//负责部分文件的抓取 M,N(be-
**FileSplitterFetch.java $dHD
*/ w7_2JS
package NetFox; )"y]_}
+F6R@@rWr
A*3R@G*h
import java.io.*; 8hvh xp
import java.net.*; L&~>(/*7U
l,1.6
iTeFy-Ct
public class FileSplitterFetch extends Thread { DT#Z6A
Mer\W6e"e
pPZ^T5-ks
String sURL; //File URL /4u:5G
long nStartPos; //File Snippet Start Position 8\8%FSrc
long nEndPos; //File Snippet End Position w7h=vy n?
int nThreadID; //Thread's ID AmT*{Fz8
boolean bDownOver = false; //Downing is over I,!>ZG@6
boolean bStop = false; //Stop identical c#(&\g2H
FileAccessI fileAccessI = null; //File Access interface rDU"l{cg
WFFpW{
~uu~NTz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WWWfQ_u2
{ 4$b9<:M_
this.sURL = sURL; '#x<Fo~hT
this.nStartPos = nStart; Q$DF3[NC
this.nEndPos = nEnd; DR#[\RzNI
nThreadID = id; ?8)$N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dv+:d4|"
} 8^dsx1U#
z50f$!?
*g/@-6
public void run() T 9?!.o
{ VEg/x z4c
while(nStartPos < nEndPos && !bStop) @5(HRd
{ `pd1'5Hm
60Obek`
YiPp#0T[Gx
try{ J*O$)K%Hx
URL url = new URL(sURL); 'k[gxk|d2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G6x2!Ny
httpConnection.setRequestProperty("User-Agent","NetFox"); sOW,hpNW
String sProperty = "bytes="+nStartPos+"-"; >@U lhJtW
httpConnection.setRequestProperty("RANGE",sProperty); 4WV)&50
Utility.log(sProperty); S~ 3|
)Z2t=&Nw
<0I=XsE1iX
InputStream input = httpConnection.getInputStream(); k~b8=$
//logResponseHead(httpConnection); QYTwGThWR
U9p^?\-=
_a,XL<9I
byte[] b = new byte[1024]; hKW!kA=gZ
int nRead; {:9P4<%H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z?8Sie
{ 6 _\j_$
nStartPos += fileAccessI.write(b,0,nRead); 4i o02qd 4
//if(nThreadID == 1) 3$ 1 z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '$n#~/#}
} >jDx-H.N
;M Z@2CO
[M6/?4\
Utility.log("Thread " + nThreadID + " is over!"); xF3H\`{4x
bDownOver = true; /q8?xP.
//nPos = fileAccessI.write (b,0,nRead); 15FGlO<<
} 7'xds
catch(Exception e){e.printStackTrace ();} ,W/D0
} S+YbsLf
} F I\V6\B/
VG`A* Vj
>zDnJb&"&
//打印回应的头信息 tY=n("=2
public void logResponseHead(HttpURLConnection con) SbW6O_
{ ba
for(int i=1;;i++) O(E-ox~q
{ sIJ37;ZA
String header=con.getHeaderFieldKey(i); ;"/ "
if(header!=null) 'u2Qq"d+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oFRb+H(E
Utility.log(header+" : "+con.getHeaderField(header)); +iPS=?S
else ~ Qt$)
break; ~:srm#IX
} "V`MNZ
} {L8(5
vv,(ta@t2
}`9}Q O
public void splitterStop() r8~U@$BBK
{ 2O5yS
bStop = true; Aq{m42EAj
} P!";$]+
_9Ig`?<>I
t%AW0#TZ
} *7I=vro
Ucnit^,
!Jj=H()}
/* YtrMJ"
**FileAccess.java VRoeq {
*//文件访问(定位，写) G#! j`
package NetFox; '4A8\&lQO
import java.io.*; cZ7b$MZ%9
-j9R%+YW<
.j4IW3)
public class FileAccessI implements Serializable{ P + nT%
mYk5f_}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X3Vpxtb
RandomAccessFile oSavedFile; n.y72-&v
long nPos; AsM""x1Ix
hGF(E*
mHox
public FileAccessI() throws IOException *#;rp~
{ T+2I:W%
this("",0); [M2,bc8SJV
} p$@=N6)I.k
GKPqBi[rO
/kVy#sT|
public FileAccessI(String sName,long nPos) throws IOException ?lU]J]
{ y\@;s?QL
oSavedFile = new RandomAccessFile(sName,"rw"); ASaG }h
this.nPos = nPos; !U/:!e`N
oSavedFile.seek(nPos); (.!q~G
} N1(}3O
SJ7>*Sa(u$
j&Ayk*
public synchronized int write(byte[] b,int nStart,int nLen) i4!n Oyk
{ ^B?koU l^
int n = -1; j>R7OGg'
try{ a@,tf'Sr
oSavedFile.write(b,nStart,nLen); S-yd-MtQp
n = nLen; Z#;ieI\
} tQJ@//C\z
catch(IOException e) '7'cKp
{ OG 5n9sx
e.printStackTrace (); rf1nC$Sop
} ;Xgy2'3
=OO_TPEZ
kZGhE2np
return n; /IV:JVT
} x)vYc36H
{Rw~G&vQ
8gBqur{
} +I\bs.84
o(~JZik
P!YT{}
/* G';oM;~/|
**SiteInfoBean.java ~`_nw5y
*/ .#WF'
package NetFox; on&N=TN
2#W%--
)vGRfFjw_
public class SiteInfoBean { GJy,)EO6{
#^#)OQq]
l/rhA6kEU
private String sSiteURL; //Site's URL gYzKUX@
private String sFilePath; //Saved File's Path 9fl !CG
private String sFileName; //Saved File's Name sQihyq6U;
private int nSplitter; //Count of Splited Downloading File J;q3 fa
]P<&CEk
/e{Oqhf[n
public SiteInfoBean() <JH0 &
{//nSplitter的缺省值为5 "l +Jx|h\
//default value of nSplitter is 5 @1Zf&'/6
this("","","",5); x=au.@psBS
} V`fh,(:
J;_JHlK
PL+fLCk,I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ={L:q8v)
{ ,CM$A}7[
sSiteURL= sURL; Tu/JhP/g,`
sFilePath = sPath; & bw1
sFileName = sName; s:]rL&|
this.nSplitter = nSpiltter; ,$;CII v
.=@M>TZM
4qm5`o\hb
} eEc;w#
5&9(d_#H
{8B\-LUR
public String getSSiteURL() J$WIF&*0@
{ !&'xkw`
return sSiteURL; &aF_y_f\
} MzG(+B
Fsq S)
IG9Q~7@
public void setSSiteURL(String value) [?IERE!xQ
{ dNJK[1e6
sSiteURL = value; ryn)
} [Z5x_.k"I
+.lO8
`chf8
public String getSFilePath() Le3S;SY&
{ Aoo'i
return sFilePath; WX\%FJ
} )Y *?VqZn
*V"cu
,<vrDHR
public void setSFilePath(String value) "]NQTUb;
{ 3mm`8!R
sFilePath = value; IYQYW.`ly
} 9lD,aOb
l[fNftT-
%MjPQ
public String getSFileName() QKP9*dz
{ %*19S.=l
return sFileName; MW4dPoa
} PZ ogN
93!a
X ]a>
public void setSFileName(String value) ynDx'Q*N'
{ ,F-tvSc\Q
sFileName = value; ?xf;#J+{8
} wl{p,[]
eh`V#%S=
zPw R1>gL
public int getNSplitter() "pWdz}!
{ AQiP2`?
return nSplitter; - 5k4vx N}
} [y{ag{
Bs1-UI}+
=)zq%d?i;
public void setNSplitter(int nCount) _+Q$h4t
{ Asn0&Ys4
nSplitter = nCount; Gqia@>T4*N
} W?l .QQk
} vfbe=)}[
v:HgpZo+
b?bYPN+
/* zgRP!q<9tt
**Utility.java I?Zs|A
*/ ^6LFho4
package NetFox; n5JB'F)
-E500F*b
,m"ztu-
public class Utility { I+CQ,Zuf
XeB>V.<y
A5`7o9
public Utility() <eh(~
{ xXx`a\i
h#n8mtt&i
;OPCBdr
} Z*TW;h0ZQ3
{fb~`=?
//线程睡眠 j0%0yb{-^
public static void sleep(int nSecond) TcP1"wc
{ =Hx~]1
try{ N*SgP@Bt
Thread.sleep(nSecond); /SUV'J)
} nM; G; T
catch(Exception e) 28)TXRr-
{ b"Mq7&cf
e.printStackTrace (); #PrV)en
} %'t~e?d!
} uv-W/p
R|CY4G j
//日志 d=#p w*w
public static void log(String sMsg) KJ)nGoP>
{ _ <;Q=?'*
System.err.println(sMsg); B![5+
} 'iVo,m[yKU
BH-[q9pf
#LN I&5
public static void log(int sMsg) \i,cL)HM
{ rq1kj 8%2
System.err.println(sMsg); %)/f; T6
} ).]m@g:ew
} {\aSEE/'
@|GeR
"pZ3
/* |tg?b&QR
**TestMethod.java (v`;ym
*/ // }8HY)>
package NetFox; baNfS
E~>6*_?
Ft7a\vn*B
public class TestMethod { N-rmk
)RYnRC#O
qp W#!Vbx
public TestMethod() 2ZO'X9
{ ///xx/weblogic60b2_win.exe j>o +}p?3I
try{ bJ|?5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 99!{[gOv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +2zuIW.
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xo@YTol
fileFetch.start(); ^)q2\YE;
} GVEWd/:X(
catch(Exception e){e.printStackTrace ();} \u]CD}/
lkfFAwnc
k,7+=.6
} m"G N^V7
"k-ov9yK
\B2d(=~4
public static void main(String[] args) O^}v/}d
{ ?*'$(}r3
new TestMethod(); 5b#6 Y
} *|HZ&}
} JQ_gM._3
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