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)); l,2z5p
} 3tcsj0Rb
for(int i=0;i<nEndPos.length-1;i++) %YAiSSsV
{ Y,"MQFr(o
nEndPos = nStartPos[i+1]; 13az[
} M HB]'
nEndPos[nEndPos.length-1] = nFileLength; E"yf!*
} 9{#|sABGD
} "8 mulE,
.v&h>@'m
j7 3@Yi%
//启动子线程 beR)8sC3q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; */e5lRO\
for(int i=0;i<nStartPos.length;i++) twS3J)UH
{ `5&V}"lB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )t=u(:u]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0>MI*fnY"
nStartPos,nEndPos,i); Czxrn2p/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .*7UT~o=CS
fileSplitterFetch.start(); <5}du9@
} /j@r~mt/pA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LkB!:+v |B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xJGeIh5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \ \}/2#1=c
nEndPos = " + nFileLength); kweTK]mT
// fileSplitterFetch[nPos.length-1].start(); B9-[wg#0G
Z!eq/
F ;&e5G
//等待子线程结束 k4rBS
//int count = 0; A\.*+k/B
//是否结束while循环 >MrU^t
boolean breakWhile = false; =lD]sk
=1[g`b
L:Eb(z/D
while(!bStop) 5^/[]*
{ *b_54X%3
write_nPos(); jtY~-@*
Utility.sleep(500); Af<>O$$6
breakWhile = true; 1U7HS2
N|S xAg
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for(int i=0;i<nStartPos.length;i++) i8.[d5
{ V5r7eC
if(!fileSplitterFetch.bDownOver) qQvb;jO
{ uJ[Vv4N%9
breakWhile = false; 1?\Y,+
break; 3>Snd9Q
} F k;su,]_
} v{Vesf
if(breakWhile) ,&G M\FTeb
break; NkI:
7bS[\5
zmRK%a(
//count++; ^ni_%`Ag
//if(count>4) 7d)' y
// siteStop(); au*jMcq
} eS:e#>(
Kf~+jYobO
yw!`1#3.
System.err.println("文件下载结束！"); p]=;t"
} Sw'?$j^3
catch(Exception e){e.printStackTrace ();} IOl"Xgn5
} ^j}sS!p
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0B/a$NC
//获得文件长度 1A-EP@# J
public long getFileSize() [{$0E=&0
{ S '+"+%^tj
int nFileLength = -1; MX,0gap
try{ rK|&u v*b
URL url = new URL(siteInfoBean.getSSiteURL()); "s9gQAoaO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V.:A'!$#
httpConnection.setRequestProperty("User-Agent","NetFox"); Ypj)6d
>/bK?yT<
%QLYNuG
int responseCode=httpConnection.getResponseCode(); #HYkzjb
if(responseCode>=400) x`i`]6q
{ y:[]+
processErrorCode(responseCode); [HDO^6U
return -2; //-2 represent access is error o1+]6s+j}
} w[YbL2p
e}AJxBE
L-{r*ccIW
String sHeader; \w[%n0
S'p`ECfVMA
;@~*z4U
for(int i=1;;i++) N\p]+[6
{ dvF48,kr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SJ^?D8
//Utility.log(in.readLine()); N~_jiVD>
sHeader=httpConnection.getHeaderFieldKey(i); -GVG1#5
if(sHeader!=null) '$-,;vnP0
{ ?u!AHSr(
if(sHeader.equals("Content-Length")) =2)t1 H
{ u@u.N2H.%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w1(06A}/
break; {bqKb=nyZ
} D#}Yx]Q1
} [iy;}5XK
else f<p4Pkv
break; #gJ~ {tA:
} wD^do
} .|`=mx
catch(IOException e){e.printStackTrace ();} C-^%g[#
catch(Exception e){e.printStackTrace ();} ^6y4!='ci
ruA+1-<f
<;E[)tv
Utility.log(nFileLength); e -]c
E816YS='
@EOR]^?!]
return nFileLength; 1za'u_
} i)PV{3v$J
lc?mKW9
O| 6\g>ew
//保存下载信息（文件指针位置） q&d&#3Rh
private void write_nPos() 39aCwhh7v
{ JBEgiQ/
try{ p6y0W`U
output = new DataOutputStream(new FileOutputStream(tmpFile)); (X_,*3Yxk
output.writeInt(nStartPos.length); j[J@tM#
for(int i=0;i<nStartPos.length;i++) }-q`&1!t
{ 3 [)s;e
// output.writeLong(nPos); 0Q- Mxcj
output.writeLong(fileSplitterFetch.nStartPos); 2]aZe4H.
output.writeLong(fileSplitterFetch.nEndPos); ^&';\O@)
} Ma=6kX]
output.close(); H(G^O&ppdB
} ]pRfY9w
catch(IOException e){e.printStackTrace ();} +>WC^s
catch(Exception e){e.printStackTrace ();} %6IlE.*,
} k4F"UG-`
*iRm`)zC(
<V:<x
//读取保存的下载信息（文件指针位置） ,D@;i
private void read_nPos() 0fPHh>u
{ }EedHS
try{ yLgKS8b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g#'fd/?Q
int nCount = input.readInt(); *L;pcg8{
nStartPos = new long[nCount]; {NY~JFM
nEndPos = new long[nCount]; }6CXJ+-UR
for(int i=0;i<nStartPos.length;i++) ,bVS.A'o
{ EAD0<I<>
nStartPos = input.readLong(); gVnwsE
nEndPos = input.readLong(); eN]>l
} Kl aZZJ
input.close(); ||=[kjG~
} rWFcIh5
catch(IOException e){e.printStackTrace ();} KZrMf77=
catch(Exception e){e.printStackTrace ();} AvrL9D
} `*" H/QG
0;FqX*
J+71FP`ZH
private void processErrorCode(int nErrorCode) 8R\>FNk;
{ g=FDm*
System.err.println("Error Code : " + nErrorCode); =&q-[JW
} p<=(GY-
ePq13!FC/
g5tjj.
//停止文件下载 X-)RU?
public void siteStop() .~.``a
{ j\`EUC
bStop = true; r zMFof
for(int i=0;i<nStartPos.length;i++) v[{8G^Z}54
fileSplitterFetch.splitterStop(); AV:Xg4UJv
RgB6:f,
rU=b?D)n!w
} gDQkn {T.%
} +Lm3vj_N
//负责部分文件的抓取 1R=)17'O
**FileSplitterFetch.java V~(EVF{h
*/ &W=V%t>Z
package NetFox; -{X<*P4p
m:)Z6
.FIt.XPzv
import java.io.*; DtzA$|Q}
import java.net.*; )uQ-YC('0
0a"igH}
x9&-(kBU
public class FileSplitterFetch extends Thread { M{`/f@z(
YfE>Pn'r
9$7&URwSDI
String sURL; //File URL 4$yV%[j
long nStartPos; //File Snippet Start Position WnD^F>
long nEndPos; //File Snippet End Position 01U *_\
int nThreadID; //Thread's ID Jy \2I{I'
boolean bDownOver = false; //Downing is over )^4ko
boolean bStop = false; //Stop identical "pt+Fe|@c;
FileAccessI fileAccessI = null; //File Access interface )O,wRd>5
;wJ~haC
sK+ (v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException OnZF6yfN=3
{ Q*]$)D3n
this.sURL = sURL; Z+g1~\
this.nStartPos = nStart; 4L8z>9D
this.nEndPos = nEnd; _|N}4a
nThreadID = id; sU\c#|BSC"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UQ/qBbn
} k!5m@'f
vt//)*(.$
>D 97c|?c
public void run() LH4>@YPGE#
{ K*~]fy
while(nStartPos < nEndPos && !bStop) COR;e`%,
{ M :V2a<!c
~ |6dH
+ :Vrip
try{ ][,4,?T7
URL url = new URL(sURL); P''X_1oMC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "NDxgJ%J35
httpConnection.setRequestProperty("User-Agent","NetFox"); "< v\M85&
String sProperty = "bytes="+nStartPos+"-"; (:5G#?6,
httpConnection.setRequestProperty("RANGE",sProperty); U[R@x`
Utility.log(sProperty); 9M_(He -
f;gZ|a
b.s9p7:J
InputStream input = httpConnection.getInputStream(); 1"}cdq.
//logResponseHead(httpConnection); .e@>
Cp#)wxi6[y
5!Bktgk.
byte[] b = new byte[1024]; '_dzcN,z
int nRead; 3J{vt"dS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -?<4Og[^
{ LvJGvj
nStartPos += fileAccessI.write(b,0,nRead); 9AHSs,.t
//if(nThreadID == 1) 9I`Y-D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *XbI#L%>
} +E/y ~s
eWvo,4
`Gd$:qV
Utility.log("Thread " + nThreadID + " is over!"); /4$4h;_8
bDownOver = true; ?7[alV~
//nPos = fileAccessI.write (b,0,nRead); e}0:"R%E
} at6149B\)
catch(Exception e){e.printStackTrace ();} /\Z J
} )zq.4
} N j4IQ<OV
kS :\Oz\
:?Y$bX}a
//打印回应的头信息 WKmbNvN^
public void logResponseHead(HttpURLConnection con) 4f^C\i+q
{ FJNF%a)x2I
for(int i=1;;i++) Bfr'Zdw
{ PUdM[-zjh
String header=con.getHeaderFieldKey(i); \}_Yd8
if(header!=null) 93O;+Z5J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ZH,4oF
Utility.log(header+" : "+con.getHeaderField(header)); N^w'Hw0
else R?66b{O
break; G{9X)|d
} =Z G:x<Hg
} Ucdj4[/,h
rw7_5l
b;GD/UI
public void splitterStop() ?=;qK{)37
{ =Gk/k}1
bStop = true; ;8{cA_&
} gEQNs\Jn L
B>y9fI
o*g|m.SjL
} h*B|fy4K9U
nqVZqX@oE
hsKmnH@#
/* {yA$V0`N{
**FileAccess.java k0-G$|QgIp
*//文件访问(定位，写) e`>{$t
package NetFox; b6(p
import java.io.*; SLfFqc+n0
sOCs13A"
u{N,Ib 8
public class FileAccessI implements Serializable{ gk[{2HgN
6 15s5ZA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !QI\Fz?
RandomAccessFile oSavedFile; =qy=-j]
long nPos; bI)u/
iJ' xh n
7R#+Le)
public FileAccessI() throws IOException dC\ZjZZ
{ *=V7@o
this("",0); hI?sOR!
} A\_|un%
^.k |SK`U
h7*W*Bd
public FileAccessI(String sName,long nPos) throws IOException cKb)VG^
{ /2EHv.e`
oSavedFile = new RandomAccessFile(sName,"rw"); -Y Bd, k3
this.nPos = nPos; uXDq~`S
oSavedFile.seek(nPos); 6 5y+Z
} pD]0`L-HJU
rqPFU6
'TH15r@
public synchronized int write(byte[] b,int nStart,int nLen) ac kqH+'
{ *_E|@y
int n = -1; jdE5~a+
try{ oI)GKA_Ng7
oSavedFile.write(b,nStart,nLen); p~noM/*2r
n = nLen; O=SkAsim
} Xc"&0v%;#
catch(IOException e) b@3_L4~
{ k+I}PuG
e.printStackTrace (); "&+"@<
} V[-jD8='3
iyj+:t/
&Ysosy*
return n; \U|ZR
} vad12WrG<
+f*OliMD
8NaqZ+5x
} 6[OzU2nB
~QvqG{bFB
Y0D}g3`
/* c@v{`d
**SiteInfoBean.java dnV[ P
*/ P!"&%d
package NetFox; vjjSKP6B
sdQkT#%y
F(t=!k,4\
public class SiteInfoBean { fN'HE#W1Xa
vN3Zr34
N^Bo .U0\
private String sSiteURL; //Site's URL !S&L*OH,
private String sFilePath; //Saved File's Path ox+ 3U
private String sFileName; //Saved File's Name 2h[85\4
private int nSplitter; //Count of Splited Downloading File gY@N~'f;"
UQB"v3Z
rj6#1kt
public SiteInfoBean() 4lBU#V7
{//nSplitter的缺省值为5 e9Nk3Sj]
//default value of nSplitter is 5 IpP~Uz
this("","","",5); -?(E_^ng
} R'S0 zp6
B" 3dQwQ
u%.$BD Hg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?JL:CBvCp
{ ,_"AT!r
sSiteURL= sURL; A^p[52`
sFilePath = sPath; 44-R!
sFileName = sName; Q'%PNrN
this.nSplitter = nSpiltter; /%Nr?V
`X3^fg
1x[)/@.'f
} ^a#X9
6 ~>FYX
_cu:aktf2
public String getSSiteURL() TC<@e<-%Sq
{ gB<3-J1R
return sSiteURL; e*L.U~ZR
} up'Tit
K# Jk _"W
QR>gt;
public void setSSiteURL(String value) 9~l hsH
{ !%c'$f/
sSiteURL = value; :rg5Kt&
} 8cA~R-
]8T!qS(UJd
yV"ZRrjO'Z
public String getSFilePath() *W kIq>
{ ,u/aT5\_
return sFilePath; SCz(5[MZJ
} 1|ra&(=)
8HP6+c%
:hM/f
public void setSFilePath(String value) pZeE61c/
{ E<c9#I=
sFilePath = value; L =8rH5
} f-%NaTI
Hbpqyl%O>
5:kH;/U
public String getSFileName() !=N"vD*
{ NM06QzE
return sFileName; R%'^gFk8
} KhMSL
\.3D~2cU
yfm^?G|sW
public void setSFileName(String value) )4&cph';
{ >hr{JJe
sFileName = value; 3.qTLga|}
} p1|f<SF')
Rb{U+/gq
=X.9,$Y
public int getNSplitter() ;dzL}@we
{ WASU0
return nSplitter; vo#UtN:q
} 9F*+YG!
a(0*um(
('hEr~&
public void setNSplitter(int nCount) xa pq*oj
{ ?G-e](]^<
nSplitter = nCount; G 8V,
} Yk5}`d!:
} %y%j*B!%
)kkhJI*v
.3MIcj=p
/* 7K5P8N ,
**Utility.java Gqy,u3lE
*/ 0JJS2oY/
package NetFox; zBe8,, e
a!u rew#
&T}''
public class Utility { a@0BBihz
w18y}mS"H
?A )hN8
public Utility() Jyqc2IH
{ 'GL*u#h
BouTcC
)uqA(R>
} qvv2O1c"A
= hN !;7G
//线程睡眠 PxfY&;4n!
public static void sleep(int nSecond) m]cHF.:5
{ "|HDGA5
try{ xSBc-u#< G
Thread.sleep(nSecond); U_{Ux2
} g{P%s'%*
catch(Exception e) Y}vr>\
{ "&%#!2
e.printStackTrace (); !0dNQ[$82
} =lVK IW
} uy}%0vLo
7H|$4;X^
//日志 3yNU$.g
public static void log(String sMsg) A2nqf^b{#
{ ~wVd$%7`
System.err.println(sMsg); m{7(PHpw
} nO)X!dp}J
0p@k({]<
;IpT} ,
public static void log(int sMsg) !S_^94b@
{ c-Pw]Ju
System.err.println(sMsg); .YZgOJi
} R+7oRXsu
} po}F6m8bX
BY]i;GVq
q@jq0D)g
/* =Z+nX0qF
**TestMethod.java E(i[o?
*/ )<xypDQ
package NetFox; 3S&U!
TET`b7G
0JD~M\-!^a
public class TestMethod { .&x}NYX4
7^Yk`Z?|a
8Mbeg ,P
public TestMethod() >[1W:KQA
{ ///xx/weblogic60b2_win.exe nIvJrAm4k
try{ /QEiMrz@6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /o2P+Xr8"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $8crN$ye
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^`D=GF^tX
fileFetch.start(); GAc{l=vT'
} @EoZI~
catch(Exception e){e.printStackTrace ();} dCFlM&(i
W@2vjz
\-*eL;qP
} nL?oTze*p
Tb1U^E:
[Ym
public static void main(String[] args) SAY f'[|w
{ ~xIjF1Z
new TestMethod(); v~/~@jv
} J/6`oh?,Q
} RJeSi`19T)
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