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)); fW[_+r]
} ?Cc$]
for(int i=0;i<nEndPos.length-1;i++) x;*VCs
{ lvG3<ls0K$
nEndPos = nStartPos[i+1]; . *Z#cq0
} TiTYs
nEndPos[nEndPos.length-1] = nFileLength; 0x6@{0
} )biX8yqhR
} /T{mS7EpYc
sbpu qOL
,qYf#fU#7
//启动子线程 ={OCa1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KM EXT$p
for(int i=0;i<nStartPos.length;i++) gMCy$+?
{ a3*.,%d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _5Bu [I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <)"iL4 kDI
nStartPos,nEndPos,i); )~G8 LZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NCp%sGBmG
fileSplitterFetch.start(); x9TuweG
} cFe V?a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;,R[]B01u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E=3#TBd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \?[O,A
nEndPos = " + nFileLength); Jr|K>
// fileSplitterFetch[nPos.length-1].start(); YALyZ.d
w:n(pLc<
Un~]Q?w
//等待子线程结束 z)r8?9u
//int count = 0; \gjl^#;
//是否结束while循环 Y{`3`Pg&N
boolean breakWhile = false; qNhH%tYQ
P:jDB{
7Z9.z4\
while(!bStop) "hJ7 Vv_
{ {P,>Q4N
write_nPos(); aS2a_!f
Utility.sleep(500); 8U8P g2
breakWhile = true; JB641nv
L)@`58Eil
g6HphRJ5s
for(int i=0;i<nStartPos.length;i++) T,A!5V>cX
{ 5R&x{jf$
if(!fileSplitterFetch.bDownOver) |)~Ex 9%ev
{ wbn^R'
breakWhile = false; 7cy+Nz
break; Fa6H(L3
} j'#)~>b
} 9@JlaY)0
if(breakWhile) "K/[[wX\b
break; +?ws !LgF
U;^CU!a
j0Id!o
//count++; S5zpUF=
//if(count>4) CD*f4I#d
// siteStop(); f6@^Mg
} ]:[)KZ~
))8Emk^Q{
)zo#1$C-
System.err.println("文件下载结束！"); = E##},N"
} L.R"~3
catch(Exception e){e.printStackTrace ();} IS3e|o*]MP
} U]+b`m
GG@iKLV
d<e+__2
//获得文件长度 {Q}!NkF1
public long getFileSize() U&tfl/
{ yd\5Z[iEp
int nFileLength = -1; Krt$=:m|1
try{ f>.`xC{
URL url = new URL(siteInfoBean.getSSiteURL()); 7Y$4MMNQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UUt~W
httpConnection.setRequestProperty("User-Agent","NetFox"); ZJiuj!
$`-SVC
1jR=h7^=
int responseCode=httpConnection.getResponseCode(); S.zg&
if(responseCode>=400) ,<R>Hiwg/s
{ WRN8#b
processErrorCode(responseCode); WsG"x>1n
return -2; //-2 represent access is error 7-g]A2N
} $%N;d>[U,
3sd{AkD^
P2A]qX
String sHeader; 5WrIg(l
O6*'gnke
* ePDc'
for(int i=1;;i++) \<0G kp
{ FN{H\W1cf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xkk@{}J\
//Utility.log(in.readLine()); Qivf|H619
sHeader=httpConnection.getHeaderFieldKey(i); G.A=hGw
if(sHeader!=null) SaX,^_GY
{ lo IL{2
if(sHeader.equals("Content-Length")) 0R2S@4%Y
{ bn^mL~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -N /8Ho
break; }.fZy&_
} "t3uW6&
} tal>b]B;
else $9LGdKZ_D
break; B;Q`vKY
} yoq\9* ?u^
} YD0vfwh
catch(IOException e){e.printStackTrace ();} yBXkN&1=%;
catch(Exception e){e.printStackTrace ();} =|j*VF2y"
(6b?ir~
!3b|*].B
Utility.log(nFileLength); I{*.htt{
tkm~KLWV&7
sK""
return nFileLength; -$sl!%HO%
} &sr:\Qn X/
PU]7c2.y
5p#o1I
//保存下载信息（文件指针位置） iZDb.9@&t
private void write_nPos() !>a&`j2:W
{ 8o%<.]
try{ df21t^0/
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~:ub
output.writeInt(nStartPos.length); U#UVenp@
for(int i=0;i<nStartPos.length;i++) Kd AR)EU>
{ )eTnR:=
// output.writeLong(nPos); nsr _\F\
output.writeLong(fileSplitterFetch.nStartPos); @4W\RwD
output.writeLong(fileSplitterFetch.nEndPos); di)noQXkB-
} L:k@BCQM
output.close(); 7>W+Uq
} 9}'l=b:Jms
catch(IOException e){e.printStackTrace ();} WNF=NNO-R
catch(Exception e){e.printStackTrace ();} W_e-7=6
} "W,"qFx
?h>%Ix
.5Z,SGBf
//读取保存的下载信息（文件指针位置） H$=h-
private void read_nPos() pDq^W@Rq
{ b3y,4ke"
try{ Ca`/t8=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |2+F I<v4
int nCount = input.readInt(); {=pP`HD0
nStartPos = new long[nCount]; z</XnN
nEndPos = new long[nCount]; N~Sue
for(int i=0;i<nStartPos.length;i++) ~,`\D7Z3
{ YDZ1@N}^B
nStartPos = input.readLong(); L&3Ar'
nEndPos = input.readLong(); !)51v {
} W~+!"^<n
input.close(); g[D,\
} VQG /g\
catch(IOException e){e.printStackTrace ();} q6m87O9
catch(Exception e){e.printStackTrace ();} pO7{3%
} 4/mj"PBKL
vt(}ga
F_M~!]<na
private void processErrorCode(int nErrorCode) mXN1b!
{ =E6i1x%j
System.err.println("Error Code : " + nErrorCode); yoQ?lh
} wZ\e3H z
n_!]B_Vd$
([4{n
//停止文件下载 _6QLnr&@j
public void siteStop() Fm[?@Z&wP
{ A]~iuUHm
bStop = true; Do[ F+Y
for(int i=0;i<nStartPos.length;i++) a s<q
fileSplitterFetch.splitterStop(); Tr}$Pb1
^JF_;~C
|Z^c#R
} V"Y Fu^L
} _ /28Cw
//负责部分文件的抓取 q%=7<( w
**FileSplitterFetch.java oRJP5Y5na
*/ M@LaD 5
package NetFox; U~zN*2-
iYfLo">
l.NkS
import java.io.*; ,*}g r
import java.net.*; $0`$)(Y
k~s>8N:&G
/xm} ?t0U
public class FileSplitterFetch extends Thread { K&gc5L
JXR/K=<^
L!}j3(I
String sURL; //File URL 5\*wX.wp
long nStartPos; //File Snippet Start Position 2"{]A;@
long nEndPos; //File Snippet End Position !A^w6Q;`V
int nThreadID; //Thread's ID 2O)Kn q
boolean bDownOver = false; //Downing is over RxDxLU2kt
boolean bStop = false; //Stop identical yfw>y=/p
FileAccessI fileAccessI = null; //File Access interface RT+30Q?
%[bO\,
}zfLm`vJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yOCcp+`T}
{ 4`5Qt=}
this.sURL = sURL; E,yzy[gl
this.nStartPos = nStart; Vwh&^{Eh
this.nEndPos = nEnd; z&yb_A:>
nThreadID = id; z1KC$~{O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{lDof>
} /*p?UW<*4
*$Wx*Jo
Kd[`mkmS
public void run() ,DUQto
{ 2Z9gOd<M~
while(nStartPos < nEndPos && !bStop) G|Yp<W%o
{ Px?At5
~aq?Kk
2] wf`9ZH
try{ Q{|'g5(O
URL url = new URL(sURL); `::(jW.KO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UeiJhH,u
httpConnection.setRequestProperty("User-Agent","NetFox"); wbF1>{/"
String sProperty = "bytes="+nStartPos+"-"; L"vG:Mq@D
httpConnection.setRequestProperty("RANGE",sProperty); ^)P5(fJ
Utility.log(sProperty); I8oKa$RF
AiHDoV+-
'*{Rn7B5
InputStream input = httpConnection.getInputStream(); 1X_!%Z
//logResponseHead(httpConnection); \w\47/k{
-N!soJ<
2dJ)4
byte[] b = new byte[1024]; `r0 qn'*
int nRead; n7!Lwq2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) % |Gzht\
{ X|lmH{kf
nStartPos += fileAccessI.write(b,0,nRead); -clg'Aa;.
//if(nThreadID == 1) N*)8L[7_;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \]:NOmI^'
} ghd[G}
j tkPi)QR
`[u>NEb
Utility.log("Thread " + nThreadID + " is over!"); i@?<]n
bDownOver = true; D@1^:'$V
//nPos = fileAccessI.write (b,0,nRead); H.G^!0j;
} ia.B@u1/
catch(Exception e){e.printStackTrace ();} [&}<!:9'
} FbNQ
} k)t8J\
M]zNW{Xt
uC ;PP=z
//打印回应的头信息 Evgq}3
public void logResponseHead(HttpURLConnection con) 0JL6EL>_
{ <y/AEY1
for(int i=1;;i++) T1W9@9,s
{ vh.tk^&
String header=con.getHeaderFieldKey(i); "YU~QOGx@
if(header!=null) X1QZEl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k#G7`dJl
Utility.log(header+" : "+con.getHeaderField(header)); (dnc7KrM
else K]Cs2IpI
break; iK0J{'
} >bP7}T
} JWjp<{Q;1
+uXnFf d^
"JGig!9
public void splitterStop() +GtGyp
{ ^7<mlr
bStop = true; &y wY?ox
} e~[z]GLO%
d33Nx)No
7027@M?A?
} `5jB|r/
~g|0uO}.
B{7/A[$%C
/* &=O1Qg=K
**FileAccess.java AS^$1i:
*//文件访问(定位，写) /3%xQK>%
package NetFox; ~4gKAD
import java.io.*; zC;lfy{f=
e[o ;l
C8zeqS^N
public class FileAccessI implements Serializable{ 9uoj3Rh<
B>21A9&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5!fW&OiY
RandomAccessFile oSavedFile; vyy\^nL
long nPos; N>\?Aeh
JNCtsfd
w:(7fu=
public FileAccessI() throws IOException ExU|EN-
{ 8ngf(#_{_n
this("",0); m*,[1oeG&
} 4?uG> ;V
UwT$IKR
[`dipLkr
public FileAccessI(String sName,long nPos) throws IOException YhR"_
{ ,QAp5I%3=
oSavedFile = new RandomAccessFile(sName,"rw"); Y}z?I%zL
this.nPos = nPos; Oj\mkg
oSavedFile.seek(nPos); OEi9 )I
} Qj[O$L0 $
4'|:SyOm
5W-M8dc6
public synchronized int write(byte[] b,int nStart,int nLen) ;itg>\p3
{ rmJ847%y`
int n = -1; <Wq{ V;$
try{ /hR]aw
oSavedFile.write(b,nStart,nLen); Mc^7FWkw
n = nLen; ?LM'5
} mSeNM
catch(IOException e) '~a$f;: Dv
{ 2 ZXF_ o
e.printStackTrace (); h%e!f#
} BBj"}~da
C{^@.8:
rJj~cPwL"
return n; z5w|+9U
} .q}k
>xgd<
zt}p-U2I
} 8iA(:Tb
g+*[CKO{
YNk|UwJi
/* ZM!~M>B9R
**SiteInfoBean.java uMZf9XUE
*/ W<l(C!{
package NetFox; brot&S2P><
T6#GlO)8)
JFdzA
public class SiteInfoBean { [)u{-
:E*U*#h/
NWj@iyi<
private String sSiteURL; //Site's URL C =U4|h~W
private String sFilePath; //Saved File's Path 4/_|Qy
private String sFileName; //Saved File's Name $Bb/GXn{\
private int nSplitter; //Count of Splited Downloading File LXl! !i%
[hbIv
pQ8+T|0x
public SiteInfoBean() GrC")Z|3u
{//nSplitter的缺省值为5 7C^ nk z
//default value of nSplitter is 5 OSk9Eb4ld
this("","","",5); h (2k;M^s
} gp2)35
{*Pp^r
![%,pip2/&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b"9,DQB=i
{ N4-J !r@#~
sSiteURL= sURL; ,iUx'U
sFilePath = sPath; l0)uu4|
sFileName = sName; #m>mYp8E.5
this.nSplitter = nSpiltter; q5PYc.E([
3}Qh`+Yj]
K4~Ox
} 5Bo)j_Qo
Z]d]RL&r
9f`Pi:*+/
public String getSSiteURL() q#Vf2U55m
{ O!tD1^O!1}
return sSiteURL; :_ox8xS4
} 3s2M$3r)6
,pzCJ@5
*Cw2h
public void setSSiteURL(String value) SGm?"esEt
{ 4uA^/]ygo
sSiteURL = value; (=9&"UH
} c2/HY8ttRD
#J_i 5KmXJ
^EOjq
public String getSFilePath() -&}E:zoe
{ 0 HmRl
return sFilePath; Q2Rj0E`
} )/'s& D
^cm^JyS)
ri ~2t3gg
public void setSFilePath(String value) z^.0eP8\j
{ y rk#)@/m
sFilePath = value; flqTx)xE
} 5@ug1F&
wn&2-m*a
mZyTo/\0
public String getSFileName() .EO1{2=
{ L8ke*O$
return sFileName; q0wVV
} (6nw8vQ
HenJlo
~@lNBF
public void setSFileName(String value) F04Etf 2k
{ at!?"u
sFileName = value; :F&WlU$L
} )w-?|2-w5
CCV~nf
C#>C59
public int getNSplitter() tUQ)q
{ d/1XL[&
return nSplitter; s9iM hCu|
} \BL9}5y
@#apOoVW>
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public void setNSplitter(int nCount) VzesqVx
{ 5oS\uX|
nSplitter = nCount; o6 /?WR9
} VM[8w`
} @d\F; o<
"|if<hx+
3nO|A: t
/* n>WS@b/o
**Utility.java tF|bxXsZ
*/ h.*|4;
package NetFox; (agdgy:#
.FUEF)
;/@R{G{+~;
public class Utility { 2olim1
9[`6f8S_$
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public Utility() }wVrmDh \
{ !T*izMX}
9=|5-?^
!r<7]nwV
} lK-I[i!
PO&`rr
//线程睡眠 f@0`,
public static void sleep(int nSecond) }MNm>3
{ cF6|IlhO
try{ jkq+j^
Thread.sleep(nSecond); isjkfl-!
} DjIs"5Iei
catch(Exception e) ~J|0G6H
{ V;"'!dVX
e.printStackTrace (); nFqMS|EN
} LdOB[W
} Dng^4VRd
>qE$:V"_5
//日志 t`Sh!e
public static void log(String sMsg) U&6f}=vC
{ :|a[6Uwl\V
System.err.println(sMsg); ydt1ED0Q-
} QUt!fF@t
157X0&EX
pPE4~g 05h
public static void log(int sMsg) <~dN23)
{ 4P8:aZM
System.err.println(sMsg); y;;@T X
} .eE5pyw+C
} $)U RY~;i
gnQd#`
STI8[e7{
/* >2a~hW|,
**TestMethod.java Sz =z TPnO
*/ n#*cVB81
package NetFox; f =Nm2(e
MYjCxy-;A
O%Mh g\#B
public class TestMethod { n3(HA
fc91D]c
tm$3ZzP4
public TestMethod() .MKxHM7
{ ///xx/weblogic60b2_win.exe Fq8Z:;C8
try{ [(C lvGx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KLX>QR@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 99`xY$
SiteFileFetch fileFetch = new SiteFileFetch(bean); iY="M_kQ_
fileFetch.start(); e*tOXXY1
} r<U }lK
catch(Exception e){e.printStackTrace ();} MStaP;|
ek9%Xk8
]?^mb n
} ,q4Y N-3
D3]_AS&\
W|:WAxJ*d
public static void main(String[] args) ||hd(_W8
{ aePk^?KbB
new TestMethod(); *`kh}
} !>M: G:K
} d/MMPge3
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