http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); HpGI\s
} yNDplm|9*
for(int i=0;i<nEndPos.length-1;i++) u!@(u!Qz
{ )8@|+'q
nEndPos = nStartPos[i+1]; 2R=Fc@MXs
} <!G%P4)
nEndPos[nEndPos.length-1] = nFileLength; dK d"2+fH
} `c.P`@KA
} J2avt
u?%FD~l:uU
45aFH}w:
//启动子线程 =tQ^t4_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;&OVV+y
for(int i=0;i<nStartPos.length;i++) ]}z"H@k
{ u6MHdCJ0y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pz0Q@n/X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HD!2|b~@
nStartPos,nEndPos,i); reI4!,x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bx._,G
fileSplitterFetch.start(); \ Dccf_(Pb
} aNDpCpy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r(OH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :D:Y-cG*n<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @Pb%dS
nEndPos = " + nFileLength); Lc! t
// fileSplitterFetch[nPos.length-1].start(); Y{7)$'At
34c+70x7
tb/`*Yl@
//等待子线程结束 JsK_q9]$e
//int count = 0; )zAATBb4.
//是否结束while循环 9r=yfc!cS
boolean breakWhile = false; U[G5<&Z^
q854k+C
jhB+ ]
while(!bStop) S.|%dz
{ H,Yrk(O-
write_nPos(); tvOyT6]
Utility.sleep(500); d;v<rw
breakWhile = true; <(_${zR
GzjC;+W
LX</xI08W
for(int i=0;i<nStartPos.length;i++) Xu& v3Y~k
{ =~q Xzq
if(!fileSplitterFetch.bDownOver) PBb'`PV
{ [E;~Y_l
breakWhile = false; +?^lnoX
break; 7-MyiCt
} V PI_pK
} fKNDl\SD
if(breakWhile) nmoC(| r
break; \ mg
+t}<e(
X!K:V~WG
//count++; ;fB!/u
//if(count>4) Bi|-KS.9
// siteStop(); gsVm)mkd
} 0RP{_1k
=|qYaXjT$
pXf5/u8&
System.err.println("文件下载结束！"); N[wyi&m4
} YLid2aF
catch(Exception e){e.printStackTrace ();} ~"22X`;h[G
} ,S-zY\XB
c1h?aP
p1fy)K2{,j
//获得文件长度 nACKSsWqI
public long getFileSize() _}Ec[c
{ m ?jF:]^
int nFileLength = -1; Mf`@X[-;
try{ 89[OaT_hs
URL url = new URL(siteInfoBean.getSSiteURL()); Jl{g"N{2u'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CxJH)H$
httpConnection.setRequestProperty("User-Agent","NetFox"); NXdT"O=P
$GX9-^og=T
[-w+ACV~
int responseCode=httpConnection.getResponseCode(); ;(;{~1~
if(responseCode>=400) ){"-J&@?
{ o'!WW
processErrorCode(responseCode); ;1>)p x**
return -2; //-2 represent access is error P*{*^DN
} T<~?7-O"
<amdPo+2D
'L ]k\GO
String sHeader; H(ds
Ui05o7xg~p
7A4_b8
for(int i=1;;i++) 6"_ytqw7
{ #H&`wMZZ:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H+Se
//Utility.log(in.readLine()); o;7_*=i
sHeader=httpConnection.getHeaderFieldKey(i); }XIUz|
if(sHeader!=null) k+y>xI,
{ o :_'R5
if(sHeader.equals("Content-Length")) TZ]o6Bb
{ TW~9<c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _U`1BmTC2
break; }?=4pGsI
} P|kfPohI=
} ip2BvN&
else `T~~yM)q
break; :WnF>zN
} v="2p8@F
} Yb Dz{m
catch(IOException e){e.printStackTrace ();} 2^T`> ?{X
catch(Exception e){e.printStackTrace ();} +!)v=NY
wEMg~Hh
iBy &#^
Utility.log(nFileLength); 3Fl!pq]
o%$'-N
B3-;]6
return nFileLength; !i*bb~
} ucgp=bye
g=_@j`
o2r)K AA
//保存下载信息（文件指针位置） V j"B/@
private void write_nPos() 3v7*@(y
{ oJbMUEQQq
try{ ecG,[1];
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5p`.RWls
output.writeInt(nStartPos.length); "L~qsFL
for(int i=0;i<nStartPos.length;i++) EG3?C
{ kqyPb$Wy
// output.writeLong(nPos); .iXIoka
output.writeLong(fileSplitterFetch.nStartPos); (2fWJ%7VG
output.writeLong(fileSplitterFetch.nEndPos); +4*jO5EZ
} Jx_BjkF
output.close(); yJGM"$
} tp3]?@0
catch(IOException e){e.printStackTrace ();} 1T@#gE["Ic
catch(Exception e){e.printStackTrace ();} :q,tmk h
} /R% Xkb
vS_Ji<W~E
Y}Gf%Xi,
//读取保存的下载信息（文件指针位置） ,ThN/GkSC
private void read_nPos() CBvvvgIo
{ .PJCBTe
try{ mcFJ__3MAV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eQQ*ZNG
int nCount = input.readInt(); J52- qR/
nStartPos = new long[nCount]; HE0@`(mCpa
nEndPos = new long[nCount]; !<2%N3l
for(int i=0;i<nStartPos.length;i++) #2\ 0#HN
{ sj& j\<(
nStartPos = input.readLong(); F.[E;gOTo
nEndPos = input.readLong(); %;-]HI
} _bm8m4Lk
input.close(); m^M sp:T,
} W+&<C#1|]
catch(IOException e){e.printStackTrace ();} TCI%Ox|a
catch(Exception e){e.printStackTrace ();} _cw~N p
} s}5,<|DL
0l&#%wmJ,
(_aM26s
private void processErrorCode(int nErrorCode) dnW#"
{ %SHgXd#X
System.err.println("Error Code : " + nErrorCode); F&= X/
} K.T.?ug;:
n?=d)[]
1x8zub B
//停止文件下载 y/(60H,{{
public void siteStop() \p%,g&^ x
{ nhZ^`mP
bStop = true; @j/|U04_Z
for(int i=0;i<nStartPos.length;i++) n#Y=y#
fileSplitterFetch.splitterStop(); Q]v><
e[ 9
;[,r./XmH
} 4[o/p8*/
} cU
//负责部分文件的抓取 a\@k5?
**FileSplitterFetch.java J+o6*t2|
*/ x$@Gp
package NetFox; _d`)N
&u}]3E'-k
:*6#(MX
import java.io.*; {^jk_G\ys
import java.net.*; lI*uF~ 'D
iu9<]1k
5tG\5
public class FileSplitterFetch extends Thread { s`63 y&Z[
|h6u%t2AY
{)L*\r
String sURL; //File URL ]XS[\qo
long nStartPos; //File Snippet Start Position 3UX/
long nEndPos; //File Snippet End Position 4?2$~\ x
int nThreadID; //Thread's ID }3DZ`8u
boolean bDownOver = false; //Downing is over >o_cf*nx
boolean bStop = false; //Stop identical /nas~{B
FileAccessI fileAccessI = null; //File Access interface r;C BA'Z
&hco3HfW
(aTpBXGr=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @}+F4Xh,L
{ Ak'=/`+p
this.sURL = sURL; T5gL
this.nStartPos = nStart; EjDr
this.nEndPos = nEnd; qQ T^d
nThreadID = id; Mr6q7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l?Qbwv}
} D]StDOmM
"t!_bma
N}rc3d#
public void run() XKQ\Ts2<k
{ !0DOj["
while(nStartPos < nEndPos && !bStop) MLk%U 4
{ WLkfo6Nw
`vc?*"
)r|Pm-:A{
try{ IQNvhl.{
URL url = new URL(sURL); UJ^MS4;I3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8^2E77s4U
httpConnection.setRequestProperty("User-Agent","NetFox"); 3:ELYn
String sProperty = "bytes="+nStartPos+"-"; V|`w/P9g4
httpConnection.setRequestProperty("RANGE",sProperty); g3Z"ri~!G
Utility.log(sProperty); ,JONc9
3U!#rz"
..a@9#D
InputStream input = httpConnection.getInputStream(); /4wPMAlb
//logResponseHead(httpConnection); CjT]!D)s
E~K5n2CI
f C_H0h3
byte[] b = new byte[1024]; &(/QJ`*8
int nRead; l`(pV ;{W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ';iLk[
{ gH<A.5 xy
nStartPos += fileAccessI.write(b,0,nRead); ^P~NE#p5
//if(nThreadID == 1) 'eDV-cB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :211T&B%A_
} + X0db
-hpC8YS
~;D5j) 9I
Utility.log("Thread " + nThreadID + " is over!"); sB+ B,DF
bDownOver = true; Y'eE({)<K
//nPos = fileAccessI.write (b,0,nRead); s_RUb
} rOA{8)jIa*
catch(Exception e){e.printStackTrace ();} Ds@nuQ
} C]GW u~QF
} -![>aqWmj1
V \Sl->:
YX{c06BHs
//打印回应的头信息 E*G{V j
public void logResponseHead(HttpURLConnection con) ]3&BLq
{ JK9 J;c#T
for(int i=1;;i++) GS&iSjw
{ ipH'}~=ID
String header=con.getHeaderFieldKey(i); K!jMW
if(header!=null) )7;E,m<:tO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gq~6jf>
Utility.log(header+" : "+con.getHeaderField(header)); 7I;A5f
else eccJt
break; ,f)#&}x*2+
} 0jmPj
} (!"&c* <
IEeh9:Km
3#Qek2
public void splitterStop() p|RFpn2ygF
{ \wM8I-f!
bStop = true; fA" VLQE
} -v &
|@Sj:^cJD
l0nm>ps'D
} _,bDv`>Ra
sMNhD/bb
G-Dc(QhU&
/* b 67l\L
**FileAccess.java cu )w6!f
*//文件访问(定位，写) wq =Ef
package NetFox; e763yd
import java.io.*; #CTeZ/g
r9y(j z
7x//4G
public class FileAccessI implements Serializable{ eYD-8*
6O| rI>D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vV*i)`IXe
RandomAccessFile oSavedFile; 0.z\YTZ9
long nPos; MNu\=p\Eq
s]'EIw}mo
{2T;^+KE
public FileAccessI() throws IOException qj:\)#I
{ A40Q~X
this("",0); [Nv)37|W
} g\Akf
SK t&BnW
vNSeNS@jxC
public FileAccessI(String sName,long nPos) throws IOException v18OUPPX
{ v!6IH
oSavedFile = new RandomAccessFile(sName,"rw"); F/w*[Xi Sh
this.nPos = nPos; v/[*Pze,C
oSavedFile.seek(nPos); Rg\D-F6:
} Yc2dq e>
,HECHA_"
(Q F-=o
public synchronized int write(byte[] b,int nStart,int nLen) A#Ne07d
{ ?4H>1Wkb
int n = -1; JN>h:
try{ Apbgm[m|{
oSavedFile.write(b,nStart,nLen); z#Db~
n = nLen; E@CK.-N|
} EPd
catch(IOException e) 0;Z] vl/|
{ `L7Cf&W\l8
e.printStackTrace (); |{9&!=/qf
} }II)<g'
0T.kwZ8
>^J
return n; |H&&80I
} h%8C_mA
o@uZU4MM
n0%5mTUN
} X1FKcWv
wuKr9W9Xa
> K s.
/* b:(t22m#?
**SiteInfoBean.java %6cbHH
*/ ES ?6
package NetFox; bsdT>|gW
G0b##-.'^
,iMdv+
public class SiteInfoBean { p@[n(?duC.
h)h%y)1
4MPR
private String sSiteURL; //Site's URL k\Z@B!VAq
private String sFilePath; //Saved File's Path FJ{6_=@D
private String sFileName; //Saved File's Name 6ac_AsFK
private int nSplitter; //Count of Splited Downloading File {ug*
-7(,*1Tk
d:JP935
public SiteInfoBean() wj 15Og?
{//nSplitter的缺省值为5 m_h$fT8 _
//default value of nSplitter is 5 Wiere0 2*
this("","","",5); Ls/*&u
} |u_fVQj
d5#z\E??
XVzsqi*Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CG]/.
{ 7=a=@D[
sSiteURL= sURL; 4azqH;i
sFilePath = sPath; lQ!(lPh
sFileName = sName; ~ugH2jiB
this.nSplitter = nSpiltter; Y lhKP;
bA\(oD+:
xwa@h}\#
} W<T Ui51Y
(kL(:P/
@BMuov
public String getSSiteURL() +c' n,O~3
{ !112u#V
return sSiteURL; I|. <
} Xh@;4n
IubzHf
_71&".A
public void setSSiteURL(String value) ~WKWx.ul
{ }%`f%/
sSiteURL = value; V?"1&m&E
} TTD#ovo'
w}0rDWuR[
@YbZ"Jb
public String getSFilePath() _V(FHjY
{ zuI7Px
return sFilePath; (&Mv!6]
} K)GpQ|4:<
?^WX]SAl
5V8`-yO9
public void setSFilePath(String value) cp2a @
{ *0x!C8*`Xe
sFilePath = value; =55V<VI
} 2hY"bpGW
k_`YVsEYP
lw_@(E]E
public String getSFileName() aj]pN,g@N
{ KN'twPFq
return sFileName; \0.!al0
} 't+'rG6x
j+[oZfH
|}Mthj9n
public void setSFileName(String value) ^+x,211f
{ >OKc\m2%Q
sFileName = value; TGuCIc0B{
} t(1gJZs>kX
T'a&
`a5,5}7v%`
public int getNSplitter() A`1-c
{ &'u%|A@
return nSplitter; ]l^"A~va
} zqxN/H]z
?MOjtAG0_~
)i[K1$x2
public void setNSplitter(int nCount) F&HvSt}l5
{ _mTNK^gB
nSplitter = nCount; `2`h4[^ [X
} # blh9.V&F
} pV*d"~T
@ 1FWBH~
jQ['f\R
/* [nLd>2P
**Utility.java `KUL4) g~
*/ g ,yB^^%
package NetFox; GW2v&Ul7(
K~+x@O*
A>6_h1
public class Utility { Awe'MGp%
x\pygzQ/
:=\`P
public Utility() d?><+!a
{ |nY+Nen7
5hfx2O)
J9P\D!
} GQ}Rxu]
j]m|}n
//线程睡眠 XsX];I{E,
public static void sleep(int nSecond) 'y7<!uo?
{ S+l>@wa)|
try{ 6C!TXV'
Thread.sleep(nSecond); jF-0fK;)*
} c3*9{Il^
catch(Exception e) +/rh8?
{ -^t&U] g
e.printStackTrace (); TIxlLOs
} |;R-q8
} lHO.pN`2
jV' tcFr4
//日志 caZEZk#r;
public static void log(String sMsg) GK&R.R]
{ FYH^axpp
System.err.println(sMsg); ;Bat--K7+
} [Vj|fy4
SDO~g~NTp
+'aG{/J
public static void log(int sMsg) mV}eMw
{ (, $Lp0mB7
System.err.println(sMsg); n +dRAIqB
} 5"w%
} Tx(=4ALY
7eG@)5Uy
,.V=y%
/* aZCxyoh+
**TestMethod.java D!D}mPi[
*/ 1~[GGl
package NetFox; ~e=KBYDBu
S9 @*g3
5K00z?kD2V
public class TestMethod { M] W5%3do
LP) IL~
QY$4D;M`g6
public TestMethod() ^?T,>ZI
{ ///xx/weblogic60b2_win.exe Q`UgtL
try{ c}w[T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MJ.Kor
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E#n:d9WA:
SiteFileFetch fileFetch = new SiteFileFetch(bean); f0g&=k{OD
fileFetch.start(); \8`^QgV`@
} kp*BAQ
catch(Exception e){e.printStackTrace ();} H}lbF0`
aq8mD^j-&
cd$,,
} }TU2o3Q
o+?Ko=vYw
,62BZyT,T,
public static void main(String[] args) >2tosxH M
{ 3,Bm"'b6
new TestMethod(); b2YOnV
} P> ~Lx
} %Z(lTvqG
点击下载更多相关资料