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)); f?zK"
} DeQ'U!?+N
for(int i=0;i<nEndPos.length-1;i++) <D;Q8
{ bu]Se6%}
nEndPos = nStartPos[i+1]; X3iRR{< @
} -G#@BtB2+
nEndPos[nEndPos.length-1] = nFileLength; iiB)/~!O
} ^i)Q CDU7
} '4lT*KN7\
wf<`J/7u
yPG\ &Bo
//启动子线程 }.V0SM6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >@"3Q`
for(int i=0;i<nStartPos.length;i++) IYg3ve`x
{ Y_>-p(IH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nk$V{(FJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o+Ti$`2<O7
nStartPos,nEndPos,i); ur,"K'w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bTy)0ta>AF
fileSplitterFetch.start(); <;0N@
} )X!DCL:16
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | 4oM+n;Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J~'Q^O3@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uNZ>oP>
nEndPos = " + nFileLength); NF(IF.8G
// fileSplitterFetch[nPos.length-1].start(); XAxI?y[c
`m;"I
SY>,kwHO
//等待子线程结束 @TPgA(5NR
//int count = 0; $0S#d@v}
//是否结束while循环 vJAAAS
boolean breakWhile = false; G[<[#$(
Sb9=$0%\
f(s3TLM
while(!bStop) K-k.=6mS
{ t,1!`/\
write_nPos(); 5QFXj)hR+4
Utility.sleep(500); h*%0@
breakWhile = true; AH87UkNL
= *;Xc-_
w$[Ds
for(int i=0;i<nStartPos.length;i++) mImbS)V
{ ?"<r9S|[O
if(!fileSplitterFetch.bDownOver) uC*:#[
{ [(hvK{)
breakWhile = false; |od4kt
break; /xm#:+Sc
} :;*#Qh3"
} kPX2e h
if(breakWhile) .6 ?>t!&W
break; } .H Fm'p
)C01fZhD
L8w76|
//count++; E,D:D3O
//if(count>4) U>_\
// siteStop(); ,dj*p,J
} CVSsB:H6e
s@)"IdSA(
EfBVu
System.err.println("文件下载结束！"); !k= 0X\5L
} azDC'.3{p
catch(Exception e){e.printStackTrace ();} ^Im%D(MY
} uJ/?+5TU
5ih"Nds[H
!ga(L3vf
//获得文件长度 Z(k\J|&9C
public long getFileSize() jle%|8m&@
{ ci_v7Jnwo
int nFileLength = -1; Bpm5dT;
try{ Xlqz8cI
URL url = new URL(siteInfoBean.getSSiteURL()); T^%n!t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n@07$lY@;
httpConnection.setRequestProperty("User-Agent","NetFox"); T:g4D z*2\
{Sr=SE
'K@{vB
int responseCode=httpConnection.getResponseCode(); A?;8%00
if(responseCode>=400) [N95.aD
{ nvs}r%1'5
processErrorCode(responseCode); VkTlPmr
return -2; //-2 represent access is error DYT -#Ht
} aa0`y
`l gjw=
)_c=mT
String sHeader; EB29vHAt~
dp[w?AMhM9
B/sBYVU
for(int i=1;;i++) [*?_
{ }@:QYTBi }
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |:e|~sism
//Utility.log(in.readLine()); csdOIF
sHeader=httpConnection.getHeaderFieldKey(i); u$%D9Z^
if(sHeader!=null) g",wkO|
{ s*)41\V0
if(sHeader.equals("Content-Length")) xf^<ec
{ 8G5)o`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Nr]8P/[~
break; HL(U~Q6JQ
} Z4HA94
} D-o7yc"K
else E&];>3C
break; s=nVoc{Yt
} 0Y6q$h>4
} $p0 /6c
catch(IOException e){e.printStackTrace ();} DD@)z0W
catch(Exception e){e.printStackTrace ();} O+E1M=R6h
S}m$,<x
S[L#M;n
Utility.log(nFileLength); %CxEZPe$
ie$`pyj!x
?}=-eJ(7e
return nFileLength; dDqr B-G
} *1Ut}
W8G9rB|T
MS st
//保存下载信息（文件指针位置） )H;pGM:
private void write_nPos() C?w<$DU
{ &$b\=
try{ TDAWI_83-
output = new DataOutputStream(new FileOutputStream(tmpFile)); t":W.q<
output.writeInt(nStartPos.length); %K%^ ]{
for(int i=0;i<nStartPos.length;i++) q?imE~&U
{ dq YDz
// output.writeLong(nPos); && DD
output.writeLong(fileSplitterFetch.nStartPos); e' U"`)S
output.writeLong(fileSplitterFetch.nEndPos); "xDx/d8B
} $>'")7z
output.close(); ':!3jZP"m
} yV J dZI
catch(IOException e){e.printStackTrace ();} G%7 4v|cd
catch(Exception e){e.printStackTrace ();} XDpfpJ,z"}
} n%0]V Xx#
}xkLD!
?~aZ#%*i8
//读取保存的下载信息（文件指针位置） $Wr\[P:
private void read_nPos() |RR%bQ^{
{ `%t$s,TiP
try{ _e?q4>B)c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "K|)<6J
int nCount = input.readInt(); 6%gB E
nStartPos = new long[nCount]; pKt-R07*
nEndPos = new long[nCount]; fJ)N:q`
for(int i=0;i<nStartPos.length;i++) MvFM,
{ J$#h(D%
nStartPos = input.readLong(); &jV9*
nEndPos = input.readLong(); >H0) ph
} }O,U2=Hw`]
input.close(); xl+DRPzl
} zH)cU%I@.
catch(IOException e){e.printStackTrace ();} 2PVx++*]C
catch(Exception e){e.printStackTrace ();} XYqpI/s
} XJx,9trH
On{~St'V
)p$\gwr=2
private void processErrorCode(int nErrorCode) M11"<3]D
{ 4meidKw]
System.err.println("Error Code : " + nErrorCode); u(pdP"
} \C]i|]tl
H+4=|mkQ
{8^Gs^c c
//停止文件下载 `6a]|7|f
public void siteStop() lpl8h4d
{ v!NB~"LQ
bStop = true; uP{;*E3?
for(int i=0;i<nStartPos.length;i++) X}oj_zsy;^
fileSplitterFetch.splitterStop(); rQ9*J
)!'n&UxPo$
)\{'fF
} ss?]
} m"lE&AM64p
//负责部分文件的抓取 UF@IBb}0
**FileSplitterFetch.java #*!+b
*/ (Ij0AeJ#
package NetFox; F,*2#:Ki
z 0~j
x}tKewdOSe
import java.io.*; <jbj/Q )"
import java.net.*; Wgxn`6
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P3'2IzNw
public class FileSplitterFetch extends Thread { +"]oc{W!
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`kv1@aQPL
String sURL; //File URL eYJ{LPo
long nStartPos; //File Snippet Start Position _h0-
long nEndPos; //File Snippet End Position c{1V.
int nThreadID; //Thread's ID ?22d},.
boolean bDownOver = false; //Downing is over PC*m% ?+
boolean bStop = false; //Stop identical `.{U-U\
FileAccessI fileAccessI = null; //File Access interface `5~7IPl3
YecT 96%
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :3JCvrq
{ n vm^k
this.sURL = sURL; mO#I nTO
this.nStartPos = nStart; ]#F q>E
this.nEndPos = nEnd; Mv|vRx^b
nThreadID = id; p1+7<Y:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |y.zocBj
} r=h8oUNEJ*
cp$.,V
:@.C4oq
public void run() :~yzDk\I"-
{ CE)*qFs
while(nStartPos < nEndPos && !bStop) :`D'jF^S
{ QQ@9_[N
*5e<\{!
j5kA^MTG
try{ 8KFj<N>'
URL url = new URL(sURL); hQXxG/yFm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /T,zZ9=
httpConnection.setRequestProperty("User-Agent","NetFox"); zVdKYs i^
String sProperty = "bytes="+nStartPos+"-"; VsEGX@;tO
httpConnection.setRequestProperty("RANGE",sProperty); x8Q~VVZr
Utility.log(sProperty); l$F_"o?&S@
l{8CISO*
SaCx)8ul0
InputStream input = httpConnection.getInputStream(); 'f 3HKn<L
//logResponseHead(httpConnection); \I;cZ>{u"}
h-7A9:
't7Z] G
byte[] b = new byte[1024]; qk&gA}qF
int nRead; sH%&+4!3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s}wO7Df=+
{ :AZp}
nStartPos += fileAccessI.write(b,0,nRead); $57\u/(
//if(nThreadID == 1) A^-iHm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W+8^P( K
} 5:c;RRn
' PELf P8
u*hH}
Utility.log("Thread " + nThreadID + " is over!"); zhX;6= X2
bDownOver = true; 7{-@}j`
//nPos = fileAccessI.write (b,0,nRead); W,Ty=:qm*
} 3Y`>6A=
catch(Exception e){e.printStackTrace ();} zO%w_7w
} QP:9%f>=
} .:8[wI_f
mH)OB?+lq
GMBJjP&R]
//打印回应的头信息 /jR8|sb
public void logResponseHead(HttpURLConnection con) Wm(:P
{ 6+iK!&+=
for(int i=1;;i++) n'yl)HA~>`
{ #7o0dE;Kg9
String header=con.getHeaderFieldKey(i); *<r%aeG$em
if(header!=null) |CwG3&8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N+NK`
Utility.log(header+" : "+con.getHeaderField(header)); BhLZ7*
else ^#;RLSv
break; //<:k8
} ;}D-:J-z_
} pw3(t
GMdI0jaG#
]U[&uymax
public void splitterStop() !Av1Leb9$
{ Y''6NGf
bStop = true; N!L'W\H,
} r{S=Z~J
^>^\CP]
z?kd'j`FG
} Ihg~Q4t
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wu2:'y>n
/* aM$=|%9/
**FileAccess.java \45(#H<$
*//文件访问(定位，写) yp p4L|R
package NetFox; oIb) Rq!m
import java.io.*; |'<vrn
xl8#=qmCD
n+?-�
public class FileAccessI implements Serializable{ s`c?:
@Dj:4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |{f~Ks%
RandomAccessFile oSavedFile; @+&'%1
long nPos; 4gOgWBv
#V[SQ=>x[
| ]# +v@
public FileAccessI() throws IOException C_G1P)k
{ IY)5.E _
this("",0); SKR;wu
} G#0,CLGN^
#ZlM?Q
;& ~929
public FileAccessI(String sName,long nPos) throws IOException !BUi)mo
{ BI.V0@qZ
oSavedFile = new RandomAccessFile(sName,"rw"); A$@o'Q;he
this.nPos = nPos; :Fw?{0
oSavedFile.seek(nPos); Vv4H:BK$
} SA+d&H}Fc
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M/#U2!iFk
public synchronized int write(byte[] b,int nStart,int nLen) &z>q#'X;.
{ EwQae(PpA
int n = -1; :B.G)M\
try{ fhRjYYGI
oSavedFile.write(b,nStart,nLen); F\LsI;G
n = nLen; TatMf;?h&
} KO&:06V{
catch(IOException e) l.oBcg[
{ -B9S}NPo
e.printStackTrace (); q- :4=vkn
} yW("G-Nm
d}-'<Z#G
xNX'~B^4d
return n; j"hASBTgp
} 8l23%iWxe
JZ=5Bpw
{ma;G[!
} 4SR(->@
g1@wf
bSrZ{l
/* k[9A,N^lZB
**SiteInfoBean.java GNU;jSh5
*/ s;1e0n
package NetFox; z0Xa_w=
m*oc)x7'
rzu s
public class SiteInfoBean { tpYa?ZCM
tjxvN 4l
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private String sSiteURL; //Site's URL fxtxu?A>
private String sFilePath; //Saved File's Path o56kp3b)b
private String sFileName; //Saved File's Name Ae49n4J
private int nSplitter; //Count of Splited Downloading File I4ilR$jg
YPszk5hn
ezZph"&
public SiteInfoBean() zfjw;sUX
{//nSplitter的缺省值为5 v!trsjb
//default value of nSplitter is 5 `?uPn~,e8
this("","","",5); >nry0 ;z0,
} "EH,J
FkB{ SCJ
1;Xgc@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m r4b
{ "'A"U
sSiteURL= sURL; |scUo~
sFilePath = sPath; g.a| c\WH
sFileName = sName; H/J<Pd$p
this.nSplitter = nSpiltter; RrWNJ&o
vg(K$o{BT
maDz W_3
} *#2Rvt*Ox
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public String getSSiteURL() ]k*1KP
{ ,4Y*:JU4
return sSiteURL; [6RfS
} gX,9Gh
2[up+;%Y
A]?^ H<
public void setSSiteURL(String value) `o si"o9
{ 8i:[:Z
sSiteURL = value; |+NuYz?
} 16$y`~c-z
&p"(-
3hS6jS
public String getSFilePath() l h/&__
{ M<[?g5=#
return sFilePath; CgnXr/!L
} %MJ;Q?KB
8#59iQl
d+}kg
public void setSFilePath(String value) (1){A8=?o
{ <xn;bp[
sFilePath = value; de YyaV
} aws"3O% uW
.7Kk2Y
&iSD/W
public String getSFileName() Nn#u%xvJt
{ 9#rt:&xo0
return sFileName; jTSOnF}C~+
} 5 =Z!hQ}
Uix{"
qI2'u%
public void setSFileName(String value) "l,UOv c
{ =!,Gst_
sFileName = value; 9;KJr[FQV
} j|K.i/
&U&%ka<*
iZ;TYcT
public int getNSplitter() np6HUH
{ ]}2Ztr)zZ
return nSplitter; nY^Nbh0
} d 4O
Fu)Th|5GZ
-&Gfh\_NW
public void setNSplitter(int nCount) hz)9"B\S
{ f\K#>u* Q
nSplitter = nCount; \0AiCMX[
} -x'e+zT
} aqr!oxn?t
uD)-V;}P@;
a$}mWPp+f
/* W9R`A
**Utility.java 7Dt"]o"+
*/ z\.1>/Z=
package NetFox; nyhMnp#<
"=|t~`
T[.[ g/`
public class Utility { QzthTX<
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x / XkD]Hq
public Utility() R^P_{_I*"
{ ?~F. /
#*,sa
zvf3b!}
} 8tQ|-l*
{}\CL#~y
//线程睡眠 )=H{5&e#u
public static void sleep(int nSecond) Q_4Zb
{ ((MLM3zJ
try{ xncwYOz
Thread.sleep(nSecond); P s#>y&
} >XE`h9
catch(Exception e) aWaw&u
{ y1,5$0@G
e.printStackTrace (); :ba/W&-d
} K$-;;pUl
} iBvOJs
N@1p]\
//日志 0.DQO;
public static void log(String sMsg) e@jfIF0=}
{ ;CmOsA,1
System.err.println(sMsg); H/jm f5
} frH)_YJ%
-g~~]K%
nW5K[/1D
public static void log(int sMsg) XO wiHW{
{ GS%b=kc
System.err.println(sMsg); `clB43i
} #x~_`>mDN
} J}@GKNm
Yx1 D)
:s*>W$Wp4
/* se,Z#H
**TestMethod.java 4<}A]BQVkJ
*/ \"d?=uFe
package NetFox; ;|30QUYh
!Zs,-=^D
p>p'.#M
public class TestMethod { KXe ka
c{>|o
yWHne~!
public TestMethod() hTw}X.<4
{ ///xx/weblogic60b2_win.exe ;r!\-]5$
try{ tpU D0Z)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K-4tdC3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); },PBqWe
SiteFileFetch fileFetch = new SiteFileFetch(bean); :`J>bHE
fileFetch.start(); 3;y_mg
} =pp:j`B9(
catch(Exception e){e.printStackTrace ();} vlQ0gsXK
7;xKy'B\
XS|mKuMcC
} J @B4 R&V
"Ot{^_e
+/q0Y`v
public static void main(String[] args) T.@sq
{ QUp?i
new TestMethod(); Gl>E[iO
} vYzVY\
} P6we(I`"2
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