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)); B0=:A
} 2a.NWJS
for(int i=0;i<nEndPos.length-1;i++) pALB[;9g
{ )xQxc.
nEndPos = nStartPos[i+1]; M)Rp+uQ
} hM\QqZFyp
nEndPos[nEndPos.length-1] = nFileLength; ~m!>e])P?X
} qq-&z6;$
} =D5@PHpv(
p@i U}SUaE
X2@mQ&n
//启动子线程 w GZ(bKyO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =\4w" /Y
for(int i=0;i<nStartPos.length;i++) {N5g52MN
{ 7~\Dzcfk"P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4:r^6m%%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zq!2);,
nStartPos,nEndPos,i); $Fz/&;KX!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Go(8`>
fileSplitterFetch.start(); VK`_Qc#B
} :EgdV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CW\o>yh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /p\Ymq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yD1*^~loJ
nEndPos = " + nFileLength); 2DQ'h}BI
// fileSplitterFetch[nPos.length-1].start(); u-UUF
?^BsR
1@)]+* F*z
//等待子线程结束 {DNc7G
//int count = 0; SNvK8,"g
//是否结束while循环 *(?YgV
boolean breakWhile = false; O#O~A|
BT>*xZLpS
u;J=g
while(!bStop) @<vDR">
{ 0IDHoNaT<
write_nPos(); 0O-p(L=
Utility.sleep(500); 6$PfX.Fh
breakWhile = true; OD\x1,E)I
*XH?|SV
Byldt
for(int i=0;i<nStartPos.length;i++) o*p7/KvoT
{ Xz]}cRQ[
if(!fileSplitterFetch.bDownOver) aS~k.^N
{ 6/4OFvL1
breakWhile = false; "vLqYc4$
break; ^Jnp\o>
} R2]?9\II
} Jq6p5jr"
if(breakWhile) W[^XG\
break; Rp`}"x9
l^$:R~gS
LV8,nTYvE
//count++; d,<ctd
//if(count>4) }i[i{lKj
// siteStop(); t ?bq~!X
} /SMp`Q88
Y2<#%@%4
ULU ]k#
System.err.println("文件下载结束！"); d0-}Xl
} pbqa
catch(Exception e){e.printStackTrace ();} =1yUH9\,b
} &}T`[ d_Z
)>\Ne~%
?\vJ8H[bD
//获得文件长度 E}NX+ vYF
public long getFileSize() r}hj,Sq'
{ -8 &f=J)
int nFileLength = -1; ?-@hNrx
try{ ^[zF_df
URL url = new URL(siteInfoBean.getSSiteURL()); <R3S{ty
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FNc[2sI
httpConnection.setRequestProperty("User-Agent","NetFox"); o{-PT'
Nq*\{rb
0w+hf3K+:
int responseCode=httpConnection.getResponseCode(); bO2$0!=I
if(responseCode>=400) k9^P#l@p
{ $%1[<}<
processErrorCode(responseCode); Q8:u1$}
return -2; //-2 represent access is error U +mx@C_
} JC=Bxv
8:s3Q`O
|AFF*]e S
String sHeader; )3)L
H>M%5bj
(^Nf;E
for(int i=1;;i++) kJDMIh|g
{ tAc;O[L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (5yg\3Jvp
//Utility.log(in.readLine()); XLmbpEh
sHeader=httpConnection.getHeaderFieldKey(i); Opjt? ]
if(sHeader!=null) 3tr?-l[N\
{ H[>_LYZ8
if(sHeader.equals("Content-Length")) }Bc6:a
{ ~7~nU>Vv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sS-5W-&P{T
break; c&0IJ7fZG
} 8<]>q
} &)bar.vw/
else 6eS#L21*
break; :=i0$k<E/
} @L0wd>
} t#P)KcWOt
catch(IOException e){e.printStackTrace ();} q>Q|:g&:
catch(Exception e){e.printStackTrace ();} siD Sm
.5dZaI)
k*-+@U"+
Utility.log(nFileLength); |fw+{f
"%.#/!RG
;^rZ"2U l
return nFileLength; CiMy_`H
} ]AHUo;(f%
x&9I2"
F5MWxAS,>
//保存下载信息（文件指针位置） s#d# *pgzh
private void write_nPos() ZnJnjW PQ
{ x(t}H8q
try{ 55!9U:{
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^MddfBwk
output.writeInt(nStartPos.length); =} vG|
for(int i=0;i<nStartPos.length;i++) ;<MaCtDt
{ (O<lVz@8
// output.writeLong(nPos); Zy!\=-dSm
output.writeLong(fileSplitterFetch.nStartPos); Cog:6Gnw
output.writeLong(fileSplitterFetch.nEndPos); c3 wu&*p{
} +m+HC(Z
output.close(); %hTe%(e
} Jp= (Q]ab
catch(IOException e){e.printStackTrace ();} |/<iydP
catch(Exception e){e.printStackTrace ();} .7kVC
} #); 6+v
i5AhF\7F9
-_314j=`/
//读取保存的下载信息（文件指针位置） +QHhAA$
private void read_nPos() >K &b,o,[
{ KK] >0QAY
try{ d9^=#ot
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V!Joh5=a
int nCount = input.readInt(); +'KM~c?]
nStartPos = new long[nCount]; SjJUhTb
nEndPos = new long[nCount]; 7P\sn<
for(int i=0;i<nStartPos.length;i++) FcWu#}.p}
{ Cu?$!|V
nStartPos = input.readLong(); &1?Q]ZRp
nEndPos = input.readLong(); qh&K{r*T
} 6g.@I!j E
input.close(); )b-G2< kb
} >eEf|tKO
catch(IOException e){e.printStackTrace ();} FCP5EN
catch(Exception e){e.printStackTrace ();} A{c6XQR~z
} |BW956fBU
}YSH8d
6XG+YIG6w
private void processErrorCode(int nErrorCode) -[7.VP
{ nut7b
System.err.println("Error Code : " + nErrorCode); Kp&d9e{ Yc
} +Rh'VZJs
X<?;-HrS;
|aVv Lz
//停止文件下载 z[k2&=c
public void siteStop() brVT
{ :heJ5*!,
bStop = true; A%2!Hr
for(int i=0;i<nStartPos.length;i++) jG^~{7#
fileSplitterFetch.splitterStop(); zeua`jQ
y7w>/7q
Jg Xbs+.
} Zg'[.wov
} h]=chz
//负责部分文件的抓取 <B fwR$
**FileSplitterFetch.java rcbixOT
*/ C4G)anT
package NetFox; t^[{8,N
L{Th>]X
4Cfwz-Qo
import java.io.*; zH_q6@4
import java.net.*; NKGCz|- 9
JBYQ7SsAS0
dKMuo'H'%
public class FileSplitterFetch extends Thread { 2cDC6rul
Wu}Co
"E8!{
String sURL; //File URL LNg1q1P3
long nStartPos; //File Snippet Start Position dHu]wog
long nEndPos; //File Snippet End Position !uZ+r%
int nThreadID; //Thread's ID l-Xxv
boolean bDownOver = false; //Downing is over RS:0xN\JN
boolean bStop = false; //Stop identical MVj@0W33m
FileAccessI fileAccessI = null; //File Access interface Z/I!\
eGE%c1H9a
6JL 7ut
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |-R::gm
{ f>'7~69
this.sURL = sURL; t"L:3<U7
this.nStartPos = nStart; \Dc\H)
this.nEndPos = nEnd; 42C:cl} ."
nThreadID = id; ZD<,h` lZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *dQRs6
} P``hw=L
d-*9tit
a=J?[qrx
public void run() CVUDN2
{ s,}<5N]U
while(nStartPos < nEndPos && !bStop) sDF J
{ :vr,@1c
CJC|%i3
f&`*x t/
try{ h1Lp:@:|
URL url = new URL(sURL); \uYUX~}i"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >hhd9
httpConnection.setRequestProperty("User-Agent","NetFox"); 646yeQ1
String sProperty = "bytes="+nStartPos+"-"; M&K@><6k,k
httpConnection.setRequestProperty("RANGE",sProperty); ufJFS+?
Utility.log(sProperty); IQ_0[
-`RJk(
Y!`?q8z$G
InputStream input = httpConnection.getInputStream(); V.4j?\#%
//logResponseHead(httpConnection); 5[3hw4
GWW@8GNI
zZxP= c
byte[] b = new byte[1024]; T'V(%\w
int nRead; ]`NbNr]K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *Z]| Z4Q/`
{ GWhZ Mj
nStartPos += fileAccessI.write(b,0,nRead); i-<=nD&?t
//if(nThreadID == 1) A`r9"([-A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kgIWgk%
} <,GHy/u\
1t0FJ@)*
EK'&S=]
Utility.log("Thread " + nThreadID + " is over!"); TM}F9!*je
bDownOver = true; D6vn3*,&
//nPos = fileAccessI.write (b,0,nRead); 7^; OjO@8
} )&9=)G
catch(Exception e){e.printStackTrace ();} N!v@!z9Mu
} ArEpH"}@
} y(R*Z^c}d,
!G,$:t1-=V
I>xB.$A
//打印回应的头信息 EH:1Z*|Z{\
public void logResponseHead(HttpURLConnection con) q^cFD
{ C0W~Tk\C2
for(int i=1;;i++) &SM$oy#?
{ ^M9oTNk2
String header=con.getHeaderFieldKey(i); P=@lkF!\#
if(header!=null) GKSy|z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q.XsY.{
Utility.log(header+" : "+con.getHeaderField(header)); ,dp?'_q{
else pxbNeqK@p
break; vP4Ij
} s,k1KTXg<B
} IX(yajc[~M
=, 0a3D6b
g#:XN
public void splitterStop() GW#kaqC1
{ :2My|3H\
bStop = true; z]YhQIU4n8
} ob7_dWAG
AN>`M?EQ
B#MW`7c
} >2:Sv1T
c 2@@Rd~M
{XXNl)%
/* S=g-&lK
**FileAccess.java OgS8.wX
*//文件访问(定位，写) $iPN5@F
package NetFox; *\WI!%
import java.io.*; `Y;gMrp
@e,Zmx
wUeOD.;#F
public class FileAccessI implements Serializable{ |BkY"F7m9
{t:ND
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w'0M>2
RandomAccessFile oSavedFile; 0%F.]+6[O4
long nPos; PQ]9xzOg[
AL7O-D
O-5U|wA
public FileAccessI() throws IOException hyKg=Foq
{ E?mp6R]}%
this("",0); Q75^7Ga_
} ?<?C*W_
KUutC :
eW)I}z+{
public FileAccessI(String sName,long nPos) throws IOException W~F/ZrT3A
{ a~7osRmp0
oSavedFile = new RandomAccessFile(sName,"rw"); 1.H!A@
this.nPos = nPos; RG3G},Q
oSavedFile.seek(nPos); Q$0%~`t
} bW^QH-t
3x0wk9lND
yTt (fn:;
public synchronized int write(byte[] b,int nStart,int nLen) -C}59G8
{ BmFME0
int n = -1; O`jA-t
try{ S1`0d9ds#
oSavedFile.write(b,nStart,nLen); `_A?a_[*
n = nLen; PJ@,01
} *UoHzaIqz
catch(IOException e) "T%'Rp`j|
{ p.] .M"A
e.printStackTrace (); AV4HX\`{P0
} cu^*x/0,
TY\"@(Q|G
KdJx#Lc
return n; Mgs|*u-5
} K!K"}%/_
XHM"agrhSQ
W+ '}O<
} }l?_Cfvu
U<Y'.!
W7=_u+0d
/* (OcNC/9
**SiteInfoBean.java )v{41sM+
*/ -xu.=n@,
package NetFox; by]|O
<1+6O[>{
~:<@`
public class SiteInfoBean { ,(27p6!
v6-~fcX0G
'xZPIj+
private String sSiteURL; //Site's URL K}<!{/fi)
private String sFilePath; //Saved File's Path %)Uvf`Xhh4
private String sFileName; //Saved File's Name h_chZB'
private int nSplitter; //Count of Splited Downloading File E D^rWE_
-f2`qltjb
0#fG4D_
public SiteInfoBean() UX'NJ1f
{//nSplitter的缺省值为5 -0o6*?[Z
//default value of nSplitter is 5 0 ;_wAk
this("","","",5); JX/4=..
} _#D\*0J
d<Q+D1
iynS4]`U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EKd3$(^
{ Gz|%;
sSiteURL= sURL; x~9z`d{!
sFilePath = sPath; Ipz 1+ #s'
sFileName = sName; d6@jEa-
this.nSplitter = nSpiltter; c`i=(D<
oUvk2]H
<%>n@A
} 7{^4 x#NO
XBQ<
;IuK2iDt<
public String getSSiteURL() CxA\yG3L&
{ 7vpN6YP
return sSiteURL; -j`!(IJ
} Wbn[Q2h5
(OyY_`
$JhZ'Z
public void setSSiteURL(String value) k=mT!
{ uH&,%k9GVK
sSiteURL = value; {eswe
} :DMHezaU
-RH4y 2
Z&]+A,
public String getSFilePath() s1Tl.p5
{ j[/SXF\=
return sFilePath; ]opW; |{e
} qHR^0&
Cl9SPz
RZ|HwYG
public void setSFilePath(String value) 1t[;`iZ
{ fATA%eA8;
sFilePath = value; H6ky)kF&
} HZDaV&)@
YQ@dl
\)otu\3/
public String getSFileName() uRm_
{ >'ksXA4b
return sFileName; Wj4^W<IO
} !2Xr~u7a
rv,NQZ
6MQs \J6.
public void setSFileName(String value) 1<W4>~,wj
{ ,qe]fo >
sFileName = value; 5BU%%fBJ.
} Ig02M_
=XMD+
hJ;f1dZ7}
public int getNSplitter() s!@=rq
{ {UdcX~\~
return nSplitter; x&R9${e%
} h0F0d^W.
P /c Q1
Zk/' \(5
public void setNSplitter(int nCount) '9-axIj70
{ O&#S4]Y
nSplitter = nCount; `;5VH]V
} "%oH@ =
} _K0izKTA.
HPtTv}l
ASKAgU"h
/* X,WQ'|rC
**Utility.java <JL\?)}n
*/ s-,=e
package NetFox; `Di ^6UK(
fiE>H~
G2CZwm{/f
public class Utility { ka5#<J7<p
}uF[Ra
?W[J[cb
public Utility() Qp kKVLi
{ R`@8.]cpPy
q+A<g(Xu
i?GfY C2q
} a^*cZ?Ta
<XQN;{xSa
//线程睡眠 a=J@yK
public static void sleep(int nSecond) iK5]y+@8
{ +{,N X
try{ a>o"^%x
Thread.sleep(nSecond); KTG:I@|C
} '}jf#C1$c
catch(Exception e) BIxV|\k
{ h8f!<:rTS
e.printStackTrace (); '1W!xQ}E
} IajD;V
} (KT38RhA
1MbY7!?PG
//日志 R'Kt=.s<
public static void log(String sMsg) &mN'Tk
{ pU?{0xZH
System.err.println(sMsg); 81GQijq
} >_;kTy,
6gj]y^}
|av*!i5Q
public static void log(int sMsg) oLgg
{ Km6Ub?/7o
System.err.println(sMsg); K0tV'Ml#"
} i\t753<Ys
} xS=_yO9-
<8u>_o6
o3Mf:;2cC
/* BZovtm3E
**TestMethod.java $Y8>_6%+T
*/ /xl4ohL$a
package NetFox; @v>l[6]>^
Mw/?wtW
vuYO\u+ud
public class TestMethod { N]B)Fb
VZ\O9lD
^oS$>6|
public TestMethod() uQH%.A
{ ///xx/weblogic60b2_win.exe }x*7l`1
try{ Ct4LkmD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lVP9=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2>F\&
SiteFileFetch fileFetch = new SiteFileFetch(bean); R'rTE
fileFetch.start(); >%-Hj6%
} !Tv?%? 2l
catch(Exception e){e.printStackTrace ();} CPVzX%=
ZU=,f'bU
r eGm>
} ^'m\D;
*6:v}#b[
^#]c0
public static void main(String[] args) ?nQ_w0j
{ ~j=xiP
new TestMethod(); ):e+dt
} AT"!{Y "H
} Vwjk[ DOL
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