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)); =(3Qbb1i
} FDkRfhK
for(int i=0;i<nEndPos.length-1;i++) :w_Zr5H]
{ /#GX4&z
nEndPos = nStartPos[i+1]; -yy&q9
} !LVWggk1
nEndPos[nEndPos.length-1] = nFileLength; i-vhX4:bd
} tK`sVsm>
} =\eM -"r
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&&\ h%-Jc
//启动子线程 }3!83~Qbx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U"v(9m@
for(int i=0;i<nStartPos.length;i++) 4/&Us
{ zQMsS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), be|k"s|6)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y{0`+/\`
nStartPos,nEndPos,i); hc4<`W{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >JkQU e
fileSplitterFetch.start(); Xai ,
} f<= #WV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %M2.h;9]*\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @F]6[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |"8Az0[!
nEndPos = " + nFileLength); 3;zJ\a.+
// fileSplitterFetch[nPos.length-1].start(); 7[rn ,8@
Ek~Qp9B
7hZCh,O
//等待子线程结束 3ZGU?Z;R
//int count = 0; S$HzuK\f
//是否结束while循环 22"M#:r$
boolean breakWhile = false; iNUisl
|\TOSaZ
OkGg4X|9
while(!bStop) iA3d[%tBb
{ -==@7*x!Z
write_nPos(); DmEmv/N=
Utility.sleep(500); p%EU,:I6
breakWhile = true; *v)JX _
;{ u{FL
RIJ+]uir4
for(int i=0;i<nStartPos.length;i++) S5*wUd*p#
{ D|/Azy.[
if(!fileSplitterFetch.bDownOver) :{pvA;f
{ ck>|p09q'9
breakWhile = false; {";5n7<<)
break; mf=,6fx28
} AR\>P
} k!H;(B"s-
if(breakWhile) pN6!IxN$
break; $IX>o&S@|
[wG?&l$.KB
/Mb?dVwA
//count++; IzF7W?k
//if(count>4) &&4av*\I
// siteStop(); ]`0(^)U&
} N3g[,BE
d|k6#f-E
XL c&7
System.err.println("文件下载结束！"); rVd(H
} FiMP_ y*S
catch(Exception e){e.printStackTrace ();} Un@B D}@\
} ,LKY?=T$z
.",E}3zn
b2u_1P\
//获得文件长度 u`dWU}m)
public long getFileSize() ftq&<8
{ A<2_V1
int nFileLength = -1; ,u^i0uOg
try{ <use+C2
URL url = new URL(siteInfoBean.getSSiteURL()); Y,I0o{,g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L3lf28W
httpConnection.setRequestProperty("User-Agent","NetFox"); 6f,#O8]#5
6DqV1'
,+<NP}Yg#G
int responseCode=httpConnection.getResponseCode(); &:`T!n
if(responseCode>=400) @;2,TY>Di
{ Ar7vEa81
processErrorCode(responseCode); 0^nnR7
return -2; //-2 represent access is error !q=ej^(S
} \_}Y4
+Rn]6}5m\
pE@Q (9`b{
String sHeader; ]n1@!qa48
qFp }+s
unKTa*U^q
for(int i=1;;i++) ]u 4
{ :\9E%/aAD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $HT {}^B
//Utility.log(in.readLine()); O`5PX(J1&
sHeader=httpConnection.getHeaderFieldKey(i); ;W,XP#{W
if(sHeader!=null) Tm~a&p
{ ~K]5`(KV
if(sHeader.equals("Content-Length")) e}Cp;c]=
{ P,lKa.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3Xyu`zS&
break; /=&HunaxI
} =u W+>;]
} QxG:NN;jW
else XcB!9AIO
break; ce-5XqzY@
} "4"gHs
} U|VFzpJ
catch(IOException e){e.printStackTrace ();} @T[}]e
catch(Exception e){e.printStackTrace ();} T#%r\f,l0
!PJD+SrG
{^zieP!
Utility.log(nFileLength); 1eQa54n
0)n#$d>
'z7,)Q&8
return nFileLength; }@%A@A{R
} ':YFm
!j[Oyr|
GyQu?`
//保存下载信息（文件指针位置） Jk=E"I6
private void write_nPos() 'oSs5lW
{ k)j,~JH
try{ F_0vh;Jo
output = new DataOutputStream(new FileOutputStream(tmpFile)); `%_yRJd|;
output.writeInt(nStartPos.length); +EG?8L,z
for(int i=0;i<nStartPos.length;i++) '&?cW#J?
{ 6S7 =+>
// output.writeLong(nPos); ?IRp3H
output.writeLong(fileSplitterFetch.nStartPos); s8;/'?K
output.writeLong(fileSplitterFetch.nEndPos); 'Vq_/g!?1
} *9.4AW~]X
output.close(); }jTCzqHW]
} 1KwUp0%&
catch(IOException e){e.printStackTrace ();} T=Q"|S]V
catch(Exception e){e.printStackTrace ();} _0^f
} b.HfxYt(
zIc%>?w
#mu3`,9V
//读取保存的下载信息（文件指针位置） Yzo_ZvL
private void read_nPos() 'MZX"t
{ u.W}{-+kp
try{ anLSD/'4W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T^FeahA7;
int nCount = input.readInt(); 1=Npq=d
nStartPos = new long[nCount]; qy@v,a
nEndPos = new long[nCount]; n:QFwwQ`Q;
for(int i=0;i<nStartPos.length;i++) fCg"tckE
{ eru2.(1
nStartPos = input.readLong(); vb^/DMhz
nEndPos = input.readLong(); tx0`#x
} #r{`Iv?nn
input.close(); 2e~ud9,
} Gp*U2LB
catch(IOException e){e.printStackTrace ();} J*V@huF
catch(Exception e){e.printStackTrace ();} ^\|Hz\"*
} EPO*{bN7O
TNgf96) y
%K@s0uQ
private void processErrorCode(int nErrorCode) "p,TYjT?R
{ J*4byu|
System.err.println("Error Code : " + nErrorCode); )1de<# qM
} (H=7(
6k14xPj
m3o+iYkMD
//停止文件下载 kFCjko
public void siteStop() !a %6nBo
{ i qLNX)
bStop = true; (y^[k {#
for(int i=0;i<nStartPos.length;i++) y9<]F6TT
fileSplitterFetch.splitterStop(); T2Duz,
c{7<z9U
VE_%/Fs,
} H~fX>6>
} /m>%=_nz
//负责部分文件的抓取 wXj!bh8\r
**FileSplitterFetch.java E]Wnl\Be
*/ AfQ?jKk&{'
package NetFox; b \pjjb[
z>n<+tso
YGAB2`!U
import java.io.*; >$^v@jf
import java.net.*; Kterp%J?
s>d /9 b
{3V%
public class FileSplitterFetch extends Thread { 8Xo`S<8VS
`EFPY$9`D
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String sURL; //File URL 6LVJ*sjSy
long nStartPos; //File Snippet Start Position [xaglZ9HNo
long nEndPos; //File Snippet End Position FrPpRe%!
int nThreadID; //Thread's ID PxqRb
boolean bDownOver = false; //Downing is over lQt&K1m
boolean bStop = false; //Stop identical u0& aw
FileAccessI fileAccessI = null; //File Access interface cwe@W PE2
fi/[(RBG
ss8de9T"'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =%wwepz6
{ 9lT6fW`v1Q
this.sURL = sURL; xt{f+c@P
this.nStartPos = nStart; k{{iF
this.nEndPos = nEnd; ?AL;m.X-@
nThreadID = id; C^dnkuA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t&GjW6]W
} k@,&'imx
xr }jw
g%Yw Dr=0t
public void run() 3n\eCdV-b<
{ :yLSLN
while(nStartPos < nEndPos && !bStop) 8Gw0;Uu8D
{ \|OW`7Q)k
^CZ)!3qd1
"q-,140_
try{ z j[/~I
URL url = new URL(sURL); c(]NpH in
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @D<KG
httpConnection.setRequestProperty("User-Agent","NetFox"); ^p'iX4M
String sProperty = "bytes="+nStartPos+"-"; %Q)3*L
httpConnection.setRequestProperty("RANGE",sProperty); Z$8X1(o
Utility.log(sProperty); |VY+!
[CCj5N1/
3jH8pO^
InputStream input = httpConnection.getInputStream(); d#?.G3YmK
//logResponseHead(httpConnection); |.]:#)^X?
W~TT`%[
wEMh !jAbv
byte[] b = new byte[1024]; p@/i e@DX
int nRead; FIB 9W@oao
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G^Z SQ!
{ "zT#*>U
nStartPos += fileAccessI.write(b,0,nRead); E"EBj7<s
//if(nThreadID == 1) eyx;8v cM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4h|48</
} =bVaB<!
5CSihw/5
]yTMWIx#
Utility.log("Thread " + nThreadID + " is over!"); (sngq{*%%z
bDownOver = true; kF09t5Lr
//nPos = fileAccessI.write (b,0,nRead); Rf&~7h'+
} {}vB#!
catch(Exception e){e.printStackTrace ();} 3c#CEuu
} z}Qt6na]-
} ?qn0].
o6FSSKM
/Dn,;@ZwAi
//打印回应的头信息 FfDe&/,/
public void logResponseHead(HttpURLConnection con) YKjm_)8]w
{ ;ew3^i.du
for(int i=1;;i++) N8<Wm>GLX~
{ '>GZB
String header=con.getHeaderFieldKey(i); ews4qP
if(header!=null) .?gpIZv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4FmT.P
Utility.log(header+" : "+con.getHeaderField(header)); p8%/T>hK
else 0?D`|x_
break; \6UK:'5{
} }CR@XD}[
} ?a8 o.&`l
cU,]^/0Y
Us4ijR d
public void splitterStop() xMk0Xf'_
{ +Om(&\c(6
bStop = true; B&l5yI b
} {x3"/sF
)G7")I J/X
9-<EeV_/
} X8TwMt
e 1W9Z $m
Q4gsOxP
/* 3SRz14/W_R
**FileAccess.java gm**9]k^{
*//文件访问(定位，写) 83"Vh$&
package NetFox; )qGw!^8
import java.io.*; ogt<vng
,a N8`M
_z:7Dj#
public class FileAccessI implements Serializable{ 95.m^~5
\tLfB[S.5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W'Wr8~{h
RandomAccessFile oSavedFile; gO0X-fN8
long nPos; gr\UI!]F
7*bUy)UZ
Ae&470
public FileAccessI() throws IOException b' 1%g}
{ $wL zaZL|
this("",0); b?6-lYE>L
} }O_kbPNw
[P5+}@t
h J*2q"
public FileAccessI(String sName,long nPos) throws IOException by 'P}
{ 0n5{Wr$
oSavedFile = new RandomAccessFile(sName,"rw"); o!q3+Pp;}
this.nPos = nPos; !f 7CN<
oSavedFile.seek(nPos); dQD YN_
} p 8,wr )
[LDV*79Z
.>4Zt'gCt
public synchronized int write(byte[] b,int nStart,int nLen) [If%+mHdU
{ Z`L-UQJ.
int n = -1; 5)g6yV'
try{ #r\,oXTm
oSavedFile.write(b,nStart,nLen); [,A*nU$
n = nLen; "bI'XaSv
} aS ]bTYJ'
catch(IOException e) ?P<8Zw
{ QU4/hS;Ux
e.printStackTrace (); xcBV,[E{
} 84xA/BRW
p.(8ekh
jNKu5"HB
return n; [PVem
} Ce:2Tw
FW](GWp`:
-4 ~(*
} ulY8$jB
`zD]*i(
6Vr:?TI7
/* N3J T[7
**SiteInfoBean.java dMo456L
*/ 58S>B'
package NetFox; #$vQT}
z?ck*9SZX
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public class SiteInfoBean { "pQFIV,
;5i~McH# t
x4b.^5"`:
private String sSiteURL; //Site's URL %}T' 3
private String sFilePath; //Saved File's Path 9$]I3k
private String sFileName; //Saved File's Name ]+C;C
private int nSplitter; //Count of Splited Downloading File 0A]+9@W;
BKd03s=
WA~PE` U
public SiteInfoBean() ~353x%e'
{//nSplitter的缺省值为5 oP[R?zN
//default value of nSplitter is 5 $2tPqZ>
this("","","",5); %E1_)^^
} y(^hlX6gQ
PWavq?SR
6),U(e%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #*J+4aw3
{ Qyh_o
sSiteURL= sURL; /w5~ O:
sFilePath = sPath; \=3fO(
sFileName = sName; [I XX#^F
this.nSplitter = nSpiltter; C rA7lu'
wD*z >v$
E~[v.3`
} pn5A6 #
y{Fq'w!ap
ZvQ~K(3
public String getSSiteURL() ;+86q"&n
{ :6N'%LKK
return sSiteURL; $|0?$U7!
} k&<cFZU
TbK;_pg
0$saDmED
public void setSSiteURL(String value) ZUkrJ'
{ 4u!<3-3Zy
sSiteURL = value; do-mkvk
} KG2ij~v
">-mZ'$#L
Y6&B%t<bo
public String getSFilePath() ('9LUFw\
{ @i" ^b
return sFilePath; TB oN8cB}
} r.JY88"
J)148/
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public void setSFilePath(String value) ?;q
{ |=\w b^l+
sFilePath = value; z?b[ 6DLV;
} H@j D%
b*AL,n?
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public String getSFileName() 6+Y^A})(F-
{ `S&$y4|Vs
return sFileName; W5&;PkhQ6
} r )pg9}+
=7*k>]o
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public void setSFileName(String value) =m+'orJ1
{ 9rd7l6$R"
sFileName = value; .b3cn
} tB,1+I=
*irYSTA$
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public int getNSplitter() \Y?ByY
{ _NkVi_UX
return nSplitter; uyp|Xh,
} O<:"Irq\qr
xe=/T#%
DbL=2
public void setNSplitter(int nCount) xUKn
{ bPe|/wp
nSplitter = nCount; jTDaW8@L
} 52zD!(
} )`*=P}D
;q3"XLV(T[
l9zkx'xt.-
/* Z2%ySO
**Utility.java App9um3:
*/ S<-e/`p=H
package NetFox; O< \i{4}}
>~D-\,d|f
IPIas$
public class Utility { | M|5Nc>W
t:SME'~.P
WZ3GI l
public Utility() AWXBk+
{ U^xz>:~
Hp@nxtKxW
7M#irCX
} pow.@
#cZ<[K q6
//线程睡眠 K).Gj2 $
public static void sleep(int nSecond) 2brxV'tk
{ ;;3oWsil}
try{ %]iDhXLr
Thread.sleep(nSecond); Ag6^>xb^
} k4AF .U`I
catch(Exception e) {cW%i:
{ {]F};_
e.printStackTrace (); 9A-=T>|of
} 3g#
} "s6\l~+9l
Zdm7As]
//日志 _UqE -+&
public static void log(String sMsg) j\uh]8N3<
{ -VO&#Mt5u
System.err.println(sMsg); {Y(#<UDM
} ^`MGlI}
S%sD#0l
5g$]ou
public static void log(int sMsg) /jtU<uX
{ ):c)$$dn
System.err.println(sMsg); 4|]0%H~n6
} z+k[HE^S
} a9"1a'
Ei Yj`P
o-f;$]yp>
/* ;Sqn w
**TestMethod.java A0@E^bG
*/ VsrYU@V
package NetFox; &Oxf^x["]
[ 1$p}x
nc.(bb),
public class TestMethod { YIc|0[ ]*|
\?VNr2
7SyysH<H
public TestMethod() A.%MrgOOX
{ ///xx/weblogic60b2_win.exe I\,m6=q
try{ z87_/(nu
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zBKfaQI,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /M3UK
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~@Wg3'&
fileFetch.start(); X;vfbF
} 68 *~5]
catch(Exception e){e.printStackTrace ();} T0Kjnzs
dP7nR1GS
!/qQ:k-.
} 'WC> _L
us0{y7(p
yt@;yd:OEk
public static void main(String[] args) 6HK dBW$/
{ XP|qY1
new TestMethod(); eM1=r:jgE
} 0YApaL+jt
} 4L`<xX;:{
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