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)); rcOpOoU|
} eP(%+[g
for(int i=0;i<nEndPos.length-1;i++) 'g|%Ro/
{ gE`G3kgn{
nEndPos = nStartPos[i+1]; Ej F<lw
} lk1c2
nEndPos[nEndPos.length-1] = nFileLength; 05=O5<l
} ~pX&>v\T
} 0$":W
](x4q
G5kM0vs6L
//启动子线程 R^f~aLl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9'Pyo`hJ#U
for(int i=0;i<nStartPos.length;i++) STVJu![
{ %0Ulh6g;Dt
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yw\}'7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?G*XZ0u~
nStartPos,nEndPos,i); I&q:w\\z8|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *~lD;{2
fileSplitterFetch.start(); ;]i&AAbj
} RR75ke[Hs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [WRs1$5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ryW1OV6?_0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V%<<Udu<
nEndPos = " + nFileLength); fP&F$"o8
// fileSplitterFetch[nPos.length-1].start(); d[kb]lC
*P61q\2Z
yodJGGAzk
//等待子线程结束 4+$<G/K
//int count = 0; ;=5V)1~i1;
//是否结束while循环 NQ'^z
boolean breakWhile = false; B5 C]4
?0DCjh8We
#fk)Y1
while(!bStop) ,B5Ptf#
{ 0{BPT>'
write_nPos(); ^ B=x-G.
Utility.sleep(500); v"F.<Q
breakWhile = true; qaA\.h7
Hm-+1Wx
B(:Kw;r?
for(int i=0;i<nStartPos.length;i++) 6pLB`1[v
{ !_?<-f(
if(!fileSplitterFetch.bDownOver) $P866F
{ 7B"J x^
breakWhile = false; /A9Mv%zjk
break; nbMH:UY,J
} Jk}L+Xvv
} P qagep d
if(breakWhile) 69dFd!G\
break; [{}9"zB$x0
h|!B;D
oeDsJ6;
//count++; 6!n"E@Bwu
//if(count>4) SR*%-JbA
// siteStop(); vk5pnCM^3
} xv$^%(Ujp
>QE^KtZ
>m:.5][yu
System.err.println("文件下载结束！"); ^n@iCr9
} YQ,IdWav
catch(Exception e){e.printStackTrace ();} p0qQ(
} L}XEROTR
|Mo# +{~c
w_KGn17
//获得文件长度 _a+0LTo".
public long getFileSize() q)G*"
{ KjZ^\lq'
int nFileLength = -1; Pl}}!<!<z
try{ mIFS/C
URL url = new URL(siteInfoBean.getSSiteURL()); ,^26.p$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,H1J$=X'
httpConnection.setRequestProperty("User-Agent","NetFox"); i>ORCOOU
MeQ(,irr^
CV]PCq!
int responseCode=httpConnection.getResponseCode(); `DG6ollp{
if(responseCode>=400) )N)ziAy}
{ D8m?`^Zz
processErrorCode(responseCode); smIZ:L%
return -2; //-2 represent access is error "sAR<5b
} thipfS
pr;<n\Y{
6ynQCD
String sHeader; xXA$16kd
g~FB&U4c
u\t[rC=yd
for(int i=1;;i++) l]sO[`X
{ 4=o3ZRV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (pi7TSJ
//Utility.log(in.readLine()); {)4Vv`n
sHeader=httpConnection.getHeaderFieldKey(i); F#X\}MvEU
if(sHeader!=null) L9Fx Lw41
{ .Z%7+[
if(sHeader.equals("Content-Length")) px//q4U
{ n 'P:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )tFFa*Z'
break; f910drg7
} %bDd
} "sT`Dhr
else KS*W<_I
break; *n}9_V%
} *XniF~M
} qgI Jg6x/}
catch(IOException e){e.printStackTrace ();} ;jX_e(T3m
catch(Exception e){e.printStackTrace ();} ;4 ?%k )
7w>"M
,yV pB)IQ
Utility.log(nFileLength); oYJ&BPuA'
\lKQDct. -
?#04x70
return nFileLength; Rn(|
} 5Hr(9)
s$H5W`3
;lYO)Z`3\
//保存下载信息（文件指针位置） }s}9@kl;&
private void write_nPos() &CUkR6
{ MYN1zYT6j
try{ 8^dGI9N
output = new DataOutputStream(new FileOutputStream(tmpFile)); L'aMXNO
output.writeInt(nStartPos.length); $ZcmE<7k
for(int i=0;i<nStartPos.length;i++) ^jf$V#z0/
{ Dcus-,u~
// output.writeLong(nPos); \?3];+c9
output.writeLong(fileSplitterFetch.nStartPos); /3KEX{'@U
output.writeLong(fileSplitterFetch.nEndPos); yA%[u.{
} ~@'|R%jJ
output.close(); JSGUl4N
} De>pIN;B>
catch(IOException e){e.printStackTrace ();} RK rBHqh@
catch(Exception e){e.printStackTrace ();} cLR8U1k'
} NA/+bgyuT>
* +OAc`8
XJ?@l3D:
//读取保存的下载信息（文件指针位置） +Kf::[wP7
private void read_nPos() }Ecm
{ ARQ1H0_B
try{ 8$G$Rdn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i3e|j(Gs4
int nCount = input.readInt(); *,'"\n
nStartPos = new long[nCount]; ]nfS vPb
nEndPos = new long[nCount]; N"E\o,_
for(int i=0;i<nStartPos.length;i++) ioa 1n=j
{ i w m7M
nStartPos = input.readLong(); A%Bz52yg
nEndPos = input.readLong(); 'kx{0J?
} =WO{h48]
input.close(); xHD!8B)
} .zegG=q
catch(IOException e){e.printStackTrace ();} \2NiI]t]
catch(Exception e){e.printStackTrace ();} qZ1fQN1yG
} 0 ?2#SM
YLFTf1G9
E>4 \9
private void processErrorCode(int nErrorCode) )$th${pd#v
{ Uj!L:u2b
System.err.println("Error Code : " + nErrorCode); (qPZEZKx
} %+pXzw`B
<78>6u/W%
!2{MWj
//停止文件下载 ImF/RKI~ "
public void siteStop() xUSIck
{ Q|xPm:
bStop = true; u"|.]r
for(int i=0;i<nStartPos.length;i++) koqH~>ZtD
fileSplitterFetch.splitterStop(); E&[ox[g{
~4\bR
7,+:QY@
} |=h>3Z=r!
} `q xg
//负责部分文件的抓取 As)-a5!
**FileSplitterFetch.java ,%,}[q?]d
*/ bjvi`jyL3k
package NetFox; wkIH<w|jb
P}VD}lEyO
^ )+tn
import java.io.*; /5=A#G
import java.net.*; IF1?/D"<
nZ%<2
$}\.)^[}
public class FileSplitterFetch extends Thread { l|uN-{w
MT&i5!Z
SQz>e
String sURL; //File URL ]I}' [D
long nStartPos; //File Snippet Start Position L3kms6ch
long nEndPos; //File Snippet End Position [e*8hbS
int nThreadID; //Thread's ID 5,mb]v0k
boolean bDownOver = false; //Downing is over sF<4uy
boolean bStop = false; //Stop identical ](a<b@p
FileAccessI fileAccessI = null; //File Access interface I`y}Ky<q
FijzO
-AffKo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XDI@mQmzB
{ SgY>$gP9S
this.sURL = sURL; JgxOxZS`@
this.nStartPos = nStart; IGbQ L
this.nEndPos = nEnd; J7l1-
nThreadID = id; HZP`u >.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0#yo\McZ
} Y)a 7osML
@|cas|U.r
a]ftE\99
public void run() Y)!5Z.K
{ "C0oFRk
while(nStartPos < nEndPos && !bStop) -bs~{
{ h\20
F-ijGGL#
A!j&g(Z"Q
try{ (^6SF>'
URL url = new URL(sURL); E8V,".!+E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g!K(xhEO
httpConnection.setRequestProperty("User-Agent","NetFox"); Y]Xal
String sProperty = "bytes="+nStartPos+"-"; )9PQj
httpConnection.setRequestProperty("RANGE",sProperty); VvPTL8Z
Utility.log(sProperty); 2} T"|56
r?Z8_5Y
&]ImO RN
InputStream input = httpConnection.getInputStream(); IRcZyry
//logResponseHead(httpConnection); :Tjo+vw7$H
xl<Cstr
"4ovMan
byte[] b = new byte[1024]; N2x\O~7
int nRead; |#MA?oz3T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^c-1wV`/
{ v4 c_UFEh<
nStartPos += fileAccessI.write(b,0,nRead); TYB^CVSZ
//if(nThreadID == 1) P [gqv3V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D+k5e=
} o,X ?
FfP Ce5)
8-po|
Utility.log("Thread " + nThreadID + " is over!"); PR.?"$!D{
bDownOver = true; v'DL >Y
//nPos = fileAccessI.write (b,0,nRead); 8Y&(o-R0
} %*Y:Rm'>
catch(Exception e){e.printStackTrace ();} NB>fr#pb
} )TP7gLv=b
} +=:CW'B5
a|66[
9?]4s-~
//打印回应的头信息 n32BHOVE
public void logResponseHead(HttpURLConnection con) L.erP* w
{ 'GNT'y_
for(int i=1;;i++) [S*bN!t
{ d7l0;yR&+
String header=con.getHeaderFieldKey(i); jMZ{>l.v
if(header!=null) 4Kx;F 9!%~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wLNO\JP'
Utility.log(header+" : "+con.getHeaderField(header)); !v94FkS>
else b^FB[tZ\x
break; :~g=n&x
} 0h$23.
} mNs&*h}
7zy6`OP
bl:.D~@
public void splitterStop() jYuH zf
{ ` 8.d
bStop = true; mO]>(^c
} h*&-[nSo
p"Fj6T2
LL.YkYu
} q(_pk&/
4WDh8U
rr2|xL?+u
/* /1g_Uv;
**FileAccess.java ,LU/xI0O
*//文件访问(定位，写) RXLD5$s^
package NetFox; CYs:P8^
import java.io.*; MSsboSxA
] S]F&B M|
HPm12&8,
public class FileAccessI implements Serializable{ t&0pE(MO/
mmEr2\L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Qnph?t>
RandomAccessFile oSavedFile; [,$] %|6wt
long nPos; 2et7Vw
MyAi)Mz~o
I=|b3-
public FileAccessI() throws IOException tecCU[O
{ (|"KsGl
this("",0); b`fPP{mG
} X>=`{JS1
_KC()OIeC
WHMt$W}%
public FileAccessI(String sName,long nPos) throws IOException KK}^E_v
{ x.~Z9j
oSavedFile = new RandomAccessFile(sName,"rw"); z4{H=
this.nPos = nPos; M-"%4^8_
oSavedFile.seek(nPos); jBarYg
} Hj$JXo[U
WOG=Uy$
3<CCC+47
public synchronized int write(byte[] b,int nStart,int nLen) s9@/(_
{ t|%wVj?_
int n = -1; f9F@G&&Ugg
try{ [C9->`(`
oSavedFile.write(b,nStart,nLen); ON\_9\kv
n = nLen; 'eZUNX
} AWc7TW
catch(IOException e) YrL:!\p.
{ ,QdUfM
e.printStackTrace (); {-09,Q4[&
} IXe[JL:
j"9bt GX
nYLq%7}k
return n; u4, p.mZtb
} kW3V"twx
#\_N-bVu
1c8J yp
} V^As@P8,'(
5O%Q*\(
NDWpV
/* v&;q4b4
**SiteInfoBean.java C%9;~S
*/ yL7D;<!S&
package NetFox; 4U*J{''L
Om,+59ua*
!MOVv\@O
public class SiteInfoBean { hjtkq.@
#qtAFIm'
a4Qr\"Qm
private String sSiteURL; //Site's URL ]<V[H
private String sFilePath; //Saved File's Path ~DPjTR
private String sFileName; //Saved File's Name D .oX>L#:
private int nSplitter; //Count of Splited Downloading File ^y]CHr
PV<=wc^
aqSHo2]DX9
public SiteInfoBean() ^OnU;8IC
{//nSplitter的缺省值为5 \!Cix}}1
//default value of nSplitter is 5 Gt3V}"B3\
this("","","",5); DpI)qg#>V
} n*D-01vYP
XXBN Nr_CK
^$}9 Enj+Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6sJN@dFA
{ : 9wW*Ix
sSiteURL= sURL; oi^2Pvauh
sFilePath = sPath; 33z)F
sFileName = sName; ^1sX22k
this.nSplitter = nSpiltter; lTBPq?4{
r({!ejT{U
sKVN*8ia
} $!)Sgb
xDD3Y{K
t;!vjac
public String getSSiteURL() hy3j8?66
{ ;}"_hLX
return sSiteURL; [p^N].K$
} X`JWYb4
"7mYs)=
RB`Emp&T
public void setSSiteURL(String value) GVP"~I~/:
{ ]r8t^bqe
sSiteURL = value; pC2ZN
} [DpGL/Y.
e[.c^Hw
jT}3Zn
public String getSFilePath() A[`c2v-hF
{ QV,X> !Nz
return sFilePath; 'Alt+O_
} J6r"_>)z
bw\fKZ
&MKG#Y}
public void setSFilePath(String value) h U\)CM
{ {>PN}fk2QP
sFilePath = value; 6A&e2K>A
} /`McKYIP
ufyqfID
eM Ym@~4
public String getSFileName() Y /$`vgqs
{ =@q 9,H
return sFileName; q<Gn@xc'
} 5#3/
ARvT
;T0F1
public void setSFileName(String value) $N4%I4
{ Z]kk.@P
sFileName = value; 2[6>h)
} ky>0
3NAU|//J
_ZX"gHx
public int getNSplitter() G|MjKe4}
{ ^K*uP^B=
return nSplitter; BB@I|)9O(
} WJ":BK{NM
U+:oy:mz
QFt7L
public void setNSplitter(int nCount) 4gbi?UAmX
{ z(V?pHv+
nSplitter = nCount; D#Fe\8!l
} V;0{o
} aV"K%#N
^PA[fL"
o>*vG
/* Elthxj
**Utility.java 9 f$S4O5
*/ 8fA9yQ8
package NetFox; oE@{h$=
tgoOzk^
AE0d0Y~9
public class Utility { 'NCxVbyYD
B^g+_;
banie{ e
public Utility() lCT N dW+=
{ 2c:H0O 0o
Dlz||==
:aHD'K
} 'D#iT}Vu
eLE9-K+
//线程睡眠 *: )hoHp&
public static void sleep(int nSecond) 94C)63V
{ bL*;6TzRK
try{ SxV(.i'
Thread.sleep(nSecond); at7|r\`?-
} N'hj
catch(Exception e) {g9?Eio^F^
{ AdBF$nn[
e.printStackTrace (); kw)@[1U
} wXw pKm
} iC- ?F cA
5c6CH k`:
//日志 gNkx]bm
public static void log(String sMsg) Y^5X>
{ obWBX'
System.err.println(sMsg); dv3+x\`9
} [ox!MQ+s
r"#h6lYK&
5<Mht6"H
public static void log(int sMsg) _\yrR.HIa
{ h $)thW
System.err.println(sMsg); LX A1rgUWT
} yH_L<n
} N!" ]e*q
:()(P9?
{MX_t/o=f
/* XP'Mv_!Z
**TestMethod.java <jdS0YT
*/ &We1i&w
package NetFox; u*_I7.}9
UJ' +Z6d
g*$ 0G
public class TestMethod { bm1+|gssn
cGSoAK
mY"DYYR>
public TestMethod() xh[4d
{ ///xx/weblogic60b2_win.exe INwc@XB
try{ Yo0%5 noz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7Cf%v`B4D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wqDRFZ1*P
SiteFileFetch fileFetch = new SiteFileFetch(bean); g*8LdH6mq
fileFetch.start(); 6_/oVvd
} !ZP1?l30
catch(Exception e){e.printStackTrace ();} |u8hxa
X;_0"g
c)Ft#vzg&e
} #u+BjuZo
6w{^S~rqo
2,|*KN*e`W
public static void main(String[] args) kfb+OE:7
{ 0^44${bA
new TestMethod(); 3}O.B r|
} g3{)AX[Uy
} e #l/jFJU
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