http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 5WrIg(l
} a>-}\GXTA
for(int i=0;i<nEndPos.length-1;i++) n23%[#,r
{ ^K1~eb*K
nEndPos = nStartPos[i+1]; `</=AY>
} C}dKbs^g|
nEndPos[nEndPos.length-1] = nFileLength; <(u3+`f1s
} iX0]g45o
} }z9I`6[
7UeE(=Hr5
uD0(aqAZ
//启动子线程 DctX9U(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IG2`9rR
for(int i=0;i<nStartPos.length;i++) 60Xl.
{ [qO5~E`;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tal>b]B;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D;16}D
nStartPos,nEndPos,i); p 02nd.R6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SXT@& @E
fileSplitterFetch.start(); =rf)yp-D
} (Von;U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WcV\kemf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wsdB; 6%$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [RGC!}"mr
nEndPos = " + nFileLength); ,6y-.m7>
// fileSplitterFetch[nPos.length-1].start(); E-5ij,bHv3
W07-JHV%
AaCnTRG
//等待子线程结束 8gu'dG=
//int count = 0; wI1M0@}PV
//是否结束while循环 &sr:\Qn X/
boolean breakWhile = false; iMOPD}`IX
bn<I#ZH2
!9ceCnwbNN
while(!bStop) 46Y7HTwE
{ df21t^0/
write_nPos(); *Dd(+NI
Utility.sleep(500); ]*kP>
breakWhile = true; =Ov;'MC
9^b7jw
)n[`Z#
for(int i=0;i<nStartPos.length;i++) Sh~ 8jEk
{ JWUv H
if(!fileSplitterFetch.bDownOver) 1%]{0P0?[
{ kp#c:ym
breakWhile = false; )Bm^aMVl3
break; j:de}!wc
} it/C y\f
} ]XpU'/h>q;
if(breakWhile) H$=h-
break; OW[/%U>
kcma/d
WL]Wu.k
//count++; 6bA~mC^&
//if(count>4) )+Y\NO?O
// siteStop(); 6a2w-}Fs
} g#9*bF
K\Y6 cj
fxtYo,;$
System.err.println("文件下载结束！"); @'NaA SB
} =oKPMmpCZ
catch(Exception e){e.printStackTrace ();} <Vr]2mw
} lhIr]'?l
Gr"2G,,VI
wFoR,oXtL/
//获得文件长度 U#FJ8CD&u
public long getFileSize() ShsP]$Yp
{ fO^EMy\
int nFileLength = -1; .eDxIWW+ft
try{ mXN1b!
URL url = new URL(siteInfoBean.getSSiteURL()); 6"rFfdns
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gl(6m`a>
httpConnection.setRequestProperty("User-Agent","NetFox"); wZ\e3H z
n_!]B_Vd$
([4{n
int responseCode=httpConnection.getResponseCode(); [w#x5Xsn
if(responseCode>=400) dTU.XgX)1^
{ :+Z>nHe
processErrorCode(responseCode); 8'g*}[
return -2; //-2 represent access is error ?[L0LL?ce
} I;|5C=!
[u9S+:7"
B#Oc8`1Y
String sHeader; {*5;:QnT
7:R{~|R
/="D]K)%b8
for(int i=1;;i++) |]]pHC_/W
{ At^DY!3vx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NGb!7Mu9
//Utility.log(in.readLine()); [y&h_w.
sHeader=httpConnection.getHeaderFieldKey(i); @gl%A&a
if(sHeader!=null) MCWG*~f
{ u_/OTy
if(sHeader.equals("Content-Length")) 'mY,>#sT
{ {]/Jk07
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "`1of8$X7
break; W)Kpnb7
} #9W5
} nF!_q;+Vp
else W<Vzd4hR
break; :xUl+(+
} iYfLo">
} {$QF*j
catch(IOException e){e.printStackTrace ();} {dSU \':
catch(Exception e){e.printStackTrace ();} iR}i42Cu
7+Jma!o
2M(PH]D
Utility.log(nFileLength); BoiIr[ (
h+'eFAZ
$xn%i\
return nFileLength; krnk%ug
} dW=D]
?\p%Mx?
/o06hy
//保存下载信息（文件指针位置） !A^w6Q;`V
private void write_nPos() 2O)Kn q
{ RxDxLU2kt
try{ yfw>y=/p
output = new DataOutputStream(new FileOutputStream(tmpFile)); r@@eC['
output.writeInt(nStartPos.length); %[bO\,
for(int i=0;i<nStartPos.length;i++) }zfLm`vJ
{ yOCcp+`T}
// output.writeLong(nPos); 0f#a_
output.writeLong(fileSplitterFetch.nStartPos); ]zR;%p
output.writeLong(fileSplitterFetch.nEndPos); X=c ,`&^
} m=y,_Pz>U
output.close(); Y|N vBr
} Z-sN4fr a
catch(IOException e){e.printStackTrace ();} fM[fS?W
catch(Exception e){e.printStackTrace ();} kKk |@
} &u`rE""
nR|LV'(
'hHX"\|RA
//读取保存的下载信息（文件指针位置） 2Q_{2(nQb
private void read_nPos() GHsdLe=t0#
{ !vo'8r?&
try{ ][K8\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >p#d;wK4_
int nCount = input.readInt(); U@t?jTMBkO
nStartPos = new long[nCount]; VEYKrZA
nEndPos = new long[nCount]; tS/APSY
for(int i=0;i<nStartPos.length;i++) SIBIh-L
{ [,?A$Z*Z|
nStartPos = input.readLong(); f+88R=-u6S
nEndPos = input.readLong(); .$s|T
} k-PRV8WO
input.close(); PNxO\Rc
} O}iKPY8K
catch(IOException e){e.printStackTrace ();} {aa,#B]i
catch(Exception e){e.printStackTrace ();} JP% ;rAoJ
} Pv$"DEXA2
6g,3s?aT
8{=(#]
private void processErrorCode(int nErrorCode) mbG^fy'
{ WF.$gBH"
System.err.println("Error Code : " + nErrorCode); 8_,wOkk_B
} d.(]V2X.J
=d4',[O
+z?f,`.*
//停止文件下载 q>lkLHS
public void siteStop() f%%En5e+
{ 5N</Z6f'o
bStop = true; NTX+7<
for(int i=0;i<nStartPos.length;i++) [-94=|S @
fileSplitterFetch.splitterStop(); iW%0pLn
,7$uh):
kk./-G
} 3:gO7Uv
} ^>}[[:(6/
//负责部分文件的抓取 [67f;?b
**FileSplitterFetch.java `,]PM)iC
*/ -#z'A
package NetFox; XlcDF|?{.
Evgq}3
0JL6EL>_
import java.io.*; k.f:nv5JO
import java.net.*; T1W9@9,s
vh.tk^&
"YU~QOGx@
public class FileSplitterFetch extends Thread { z{+;'9C
D7'0o`|
Y`p&*O
String sURL; //File URL k yA(m;r
long nStartPos; //File Snippet Start Position ill'KPy
long nEndPos; //File Snippet End Position ED_5V@
int nThreadID; //Thread's ID T7nX8{l[RG
boolean bDownOver = false; //Downing is over 0 9'o
boolean bStop = false; //Stop identical v8(u9V%?6
FileAccessI fileAccessI = null; //File Access interface DMpd(ws
ba:^zO^
(j Q6~1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o:\j/+]
{ `D4'`Or-U
this.sURL = sURL; h/~BUg'
this.nStartPos = nStart; d'nuk#r
this.nEndPos = nEnd; n&&U9sf?
nThreadID = id; kF~e3A7C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :rc[j@|pH
} X51$5%
Fd.d(
1MFpuPJk
public void run() | (9FV^_
{ $ aBSr1
while(nStartPos < nEndPos && !bStop) 6HQwL\r79
{ A{T@O5ucj
F09AX'nj
RLX^'g+P
try{ ;XuEMq,Di
URL url = new URL(sURL); n,LKkOG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]KT,s].
httpConnection.setRequestProperty("User-Agent","NetFox"); [:'?}p
String sProperty = "bytes="+nStartPos+"-"; \`5u@Nzx
httpConnection.setRequestProperty("RANGE",sProperty); ,B>b9,~3a
Utility.log(sProperty); 3`8xh9O
$ !=:ES
[<$d@}O
InputStream input = httpConnection.getInputStream(); q9]L!V9Rv
//logResponseHead(httpConnection); LZ dNG\-
r}Av"
_ 9]3S>Rn
byte[] b = new byte[1024]; l~c>jm8.
int nRead; e!'u{>u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4'|:SyOm
{ J, >PLQAa
nStartPos += fileAccessI.write(b,0,nRead); }f*S 9V
//if(nThreadID == 1) rmJ847%y`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Wq{ V;$
} a$&6a
o:*iT=l
<7) 6*u
Utility.log("Thread " + nThreadID + " is over!"); Lxrn#Z eM
bDownOver = true; 2 -8:qmP(
//nPos = fileAccessI.write (b,0,nRead); fbkjK`_q
} P#oV ^
catch(Exception e){e.printStackTrace ();} {Oszq(A
} >:|q J$J.
} nP5fh_/
1OS3Gv8jc~
zjE4v-H:l
//打印回应的头信息 cNvcpv
public void logResponseHead(HttpURLConnection con) ( "z;Q?(
{ S3wH M
for(int i=1;;i++) qRLypm
{ 6%1o<{(%f
String header=con.getHeaderFieldKey(i); T+!kRigN~P
if(header!=null) ?!-im*~w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wB"Gw` D
Utility.log(header+" : "+con.getHeaderField(header)); 5(Oc"0''H
else #0H[RU?
break; >Sah\u`
} 4+bsG6i
} Okc*)crw
;Bi{;>3
?Qk#;~\yB
public void splitterStop() )CQ}LbXZy
{ 3Re\ T
bStop = true; DJUtuex
} \(L^ /]}G)
LXl! !i%
yK3z3"1M?
} EV$n>.
"KwKO8f
NE"fyX`
/* 7C^ nk z
**FileAccess.java OSk9Eb4ld
*//文件访问(定位，写) h (2k;M^s
package NetFox; gp2)35
import java.io.*; {*Pp^r
![%,pip2/&
m"]ys#
public class FileAccessI implements Serializable{ M+:wa@Kl
t68RWzqiG[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TaG-^bX8B
RandomAccessFile oSavedFile; HskN(Ho
long nPos; bux-t3g7+
8?XZF[D
X.<R['U&\
public FileAccessI() throws IOException l[k$O$jo
{ :B~c>:
this("",0); YZ@-0_Z
} \f#ao<vQm
Ymom 0g+f
YvX I
public FileAccessI(String sName,long nPos) throws IOException Zlo,#q
{ ") D!OW]
oSavedFile = new RandomAccessFile(sName,"rw"); qC1@p?8$
this.nPos = nPos; -^DB?j+
oSavedFile.seek(nPos); UtN>6$u
} jfamuu7
B?Skw{&
;0'v`ob'.?
public synchronized int write(byte[] b,int nStart,int nLen) Z ngJ9js
{ @35shLs
int n = -1; wP*Z/}Uum+
try{ ,jmG!qJb
oSavedFile.write(b,nStart,nLen); b??1Up
n = nLen; (P-<9y@
} K2 2Xo<3
catch(IOException e) g_U69 z
{ X Rn=;gK%J
e.printStackTrace (); +&@0;zSga
} UEUTu}4y
eHR<(8c'f
pJ[Q.QxU
return n; )VC) }
} $'q(Z@
nCU4a1rZ
.&y1gh!=
} X[<9+Q-&
at!?"u
:F&WlU$L
/* )w-?|2-w5
**SiteInfoBean.java CCV~nf
*/ Rd)QVEk>SD
package NetFox; }T,uw8?f!
CggEAi~
O;2 u1p'iP
public class SiteInfoBean { b3+PC$z2h
S6]':
1oPT8)[U
private String sSiteURL; //Site's URL >q`X%&l_
private String sFilePath; //Saved File's Path N;Bal/kd2
private String sFileName; //Saved File's Name 'Nh^SbD+_|
private int nSplitter; //Count of Splited Downloading File bd4q/w4q
.+>}},
x<(h9tB
public SiteInfoBean() /V&Y@j
{//nSplitter的缺省值为5 kN)ev?pQ[
//default value of nSplitter is 5 ~6tY\6$9f
this("","","",5); YbKW;L&Ff
} a0R]hENC
1*fA>v
RulIzv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (yfTkBy
{ q<VhP2R
sSiteURL= sURL; (P?9Jct
sFilePath = sPath; T (qu~}
sFileName = sName; cO:x{~
this.nSplitter = nSpiltter; {\B!Rjt[T
%[J( ,rm
|{ kB`
} q`P:PRgM
`f'P
cF6|IlhO
public String getSSiteURL() duI8^&|
{ \cG'3\GI
return sSiteURL; \1ZfSc
} >EY0-B
o&]qjFo\m
k;sUDmrO
public void setSSiteURL(String value) @UKd0kxPN{
{ C1=[\c~jw
sSiteURL = value; _bX)fnUu
} KjadX&JD
c\Dv3bF
utr_fFu
public String getSFilePath() U^xFqJY6
{ L$g;^@j
return sFilePath; pfT7
} (I$hw"%&
AF@C9s
_PIk,!<
public void setSFilePath(String value) ?Rdi"{.wI
{ o! 8X< o
sFilePath = value; Z]tz<YSkG
} \4ZQop
wQ5__"D
yC[}gHv
public String getSFileName() &~i1 @\]
{ *4ID$BmO
return sFileName; (<h,R@:
} "P6MLf1
/=N`P &R#
,0~=9dR
public void setSFileName(String value) T4[eBO
{ 0PN{ +<?.
sFileName = value; 6[cMPp x
} &\LbajP:+
tm$3ZzP4
.MKxHM7
public int getNSplitter() KnuqU2< {
{ SC#
return nSplitter; Vh&uSi1V
} 99`xY$
c0@v`-9
344- ~i*
public void setNSplitter(int nCount) 5q\]]LV>
{ TtzB[F
nSplitter = nCount; [Y[|:_+5
} fA8 ,wy|>
} ?g 3sv5\u
COap*
'G&w[8mqY
/* %EuSP0
**Utility.java `!i>fo~
*/ <*L8kNykK
package NetFox; E:2Or~
[Mx+t3M
p|zW2L
public class Utility { s^cHR1^
[8ih-k
o.,hCg)X
public Utility() 8O]$)E
{ ?n}L+|
c5JxKU_
>B==*,|
} dwRJ0D]&
;*8$BuD
//线程睡眠 i]P]o)
public static void sleep(int nSecond) Na4\)({
{ 0VPa=AW
try{ +S$x}b'5q
Thread.sleep(nSecond); ]c08`
} v''$qMQ)
catch(Exception e) MZ0 J/@(
{ ,ecFHkT>
e.printStackTrace (); ]\{EUx9
} G=DRz F
} 8IO4>CMkv
HM`;%0T0(
//日志 2gA6$s7
public static void log(String sMsg) _T1|_9b
{ `U(FdT
System.err.println(sMsg); kxh $R>
} KcHW>IBxdv
D ,nF0p
LVX.stN#p
public static void log(int sMsg) C&\#{m_1B
{ d;K,2
System.err.println(sMsg); \]zHM.E1
} u-D%: lz85
} Ay[6rUO
8/k*"^3
F8q|$[nH
/* BPW2WSm@<
**TestMethod.java U2;_{n*g%
*/ WmeV[iI
package NetFox; {$Qw]?Yv
Z<`QDBN"4
3qP! (*
public class TestMethod { nBR4j?':i
yN9/'c~
Mp}U>+8
public TestMethod() +d<o2n4!
{ ///xx/weblogic60b2_win.exe eGjEO&$
try{ *5u0`k^j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'bTtdFvJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `2G 0B@
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^)TZHc2a[
fileFetch.start(); DKR2b`J
} Yf1?3(0O
catch(Exception e){e.printStackTrace ();} nPE{Gp) }
8K'3iw>z
G@s rQum(
} `#R[x7bA1
*y0TtEd;
tmKHT
public static void main(String[] args) #mFIZMTRd
{ J.$N<.
new TestMethod(); EjrK.|I0
} ^8OK.iC
} \Cx2$<8
点击下载更多相关资料