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)); +EqL|
} 0%Y}CDn_
for(int i=0;i<nEndPos.length-1;i++) (_+ux1h6^
{ [d-Y1
nEndPos = nStartPos[i+1]; R=$}uDFmW
} ^<uQ9p^B
nEndPos[nEndPos.length-1] = nFileLength; V]"pM]>3X
} tA,J~|+f:
} HD1/1?y!@q
JiuA"ks)
U.b|3E/^
//启动子线程 (<@`MPI\@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k7L4~W
for(int i=0;i<nStartPos.length;i++) rz2,42H]
{ ${}9/(x/^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2- (}=N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~O!E&~
nStartPos,nEndPos,i); -v|lM8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k,; (`L
fileSplitterFetch.start(); *J >6i2M,u
} <OJqeUo+*\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M'oZK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .2_xTt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LyR<cd$W
nEndPos = " + nFileLength); A:(qF.Tm
// fileSplitterFetch[nPos.length-1].start(); QFoCi&
X?JtEQ~>
p,uM)LD
//等待子线程结束 Q`4Ia<5B
//int count = 0; }W[=O:p
//是否结束while循环 h|ib*%P_
boolean breakWhile = false; 1jAuW~
eNM"e-
2+pXtP@O
while(!bStop) w>}n1Nc$G
{ )]<^*b>
write_nPos(); hJw]hVYa
Utility.sleep(500); &OEBAtc/
breakWhile = true; {ot6ssT=D
=<zlg~i
"(kiMog-
for(int i=0;i<nStartPos.length;i++) E9t8SclV
{ "Vp:Sq9y
if(!fileSplitterFetch.bDownOver) l8_RA
{ fA[T5<66
breakWhile = false; :Z_abKt
break; '?fGI3b~/
} (v:8p!QN
} C7}iwklcsa
if(breakWhile) klY, @
break; twK3
RyM29uD
IjQgmS~G
//count++; FL&Y/5
//if(count>4) =^l`c$G<
// siteStop(); ">S1,rhgS
} w\V<6_[vv.
7s2*VKr
kho0@o+'^
System.err.println("文件下载结束！"); "gDk?w
} JE*?O*&|Q
catch(Exception e){e.printStackTrace ();} :<0lCj
} wyAh%'V
p6)6Gcx
| >yc|W
//获得文件长度 9}42s+
public long getFileSize() J~ +p7S
{ fD8GAav
int nFileLength = -1; k)y<iHR_o
try{ A1z<2.R
URL url = new URL(siteInfoBean.getSSiteURL()); Y$j!-l5z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hewc5vrL
httpConnection.setRequestProperty("User-Agent","NetFox"); P=9UK`n
&zVXd
}jFRuT;35
int responseCode=httpConnection.getResponseCode(); PpNG`_O
if(responseCode>=400) ^EW6}oj[
{ NqFfz9G)
processErrorCode(responseCode); hw)z]
return -2; //-2 represent access is error J9y}rGO
} +bb-uoZf
wqap~X
S@~ReRew2
String sHeader; R?N+./{
Nd@/U c
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for(int i=1;;i++) c|(Q[=
{ $YJi]:3&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wsc=6/#u
//Utility.log(in.readLine()); 3vQVk
sHeader=httpConnection.getHeaderFieldKey(i); m")p]B&i=
if(sHeader!=null) 0Jd>V
{ Z[,,(M
if(sHeader.equals("Content-Length")) l2wu>Ar7.
{ d>r]xXB6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J*ZcZ FbWN
break; I).eQ8:
} L}_VT J
} { Q!Xxe>6
else +apn3\_
break; c]qh)F$s8
} :3J`+V}9;
} r/0AM}[!*j
catch(IOException e){e.printStackTrace ();} qNMYZ0,
catch(Exception e){e.printStackTrace ();} $?LegX
oJ#;XR
tn(6T^u
Utility.log(nFileLength); lYr4gFOs
e"p){)*$
ec*Ni|`Z'
return nFileLength; 9J<vkxG9`
} jxYze/I
1,we:rwX
cA| n*A-j<
//保存下载信息（文件指针位置） _=cuOo"!
private void write_nPos() 0wF)bQv1
{ %/!f^PIwX
try{ !RjC0,
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,Hp7`I>/
output.writeInt(nStartPos.length); r CUs
for(int i=0;i<nStartPos.length;i++) }We-sZ/w7r
{ 3-[+g}kak?
// output.writeLong(nPos); 1&Mpx!K*T
output.writeLong(fileSplitterFetch.nStartPos); 58`Dcx,yJ
output.writeLong(fileSplitterFetch.nEndPos); %/_E8GE
} +vV?[e
output.close(); , 0?_? GO
} ^$rqyWZYp
catch(IOException e){e.printStackTrace ();} <u?\%iJ"
catch(Exception e){e.printStackTrace ();} 6\y?+H1
} 'I>geW?{QK
1p<*11
li#ep?5h^
//读取保存的下载信息（文件指针位置） gnf4H V~
private void read_nPos() 6J cXhlB`
{ wX!0KxR/Z
try{ SWT)M1O2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \vpX6!T
int nCount = input.readInt(); f>Tn#OW
nStartPos = new long[nCount]; VmXXj6l&
nEndPos = new long[nCount]; >]Dn,*R
for(int i=0;i<nStartPos.length;i++) BXytAz3
{ /NuO>kQa
nStartPos = input.readLong(); (tiE%nF+
nEndPos = input.readLong(); 6.|[;>Km
} .5A .[ZY)
input.close(); C0ORBp
} "od2i\
catch(IOException e){e.printStackTrace ();} =t|,6Vp
catch(Exception e){e.printStackTrace ();} 7dR]$~+*e
} ' wp _U/
"wxyY^"
H5CL0#I
private void processErrorCode(int nErrorCode) LF+E5{=:R
{ a?X@ D<.;
System.err.println("Error Code : " + nErrorCode); xF 3Z>
} $j4/ohwTDY
&,\my-4c>
wzY{ii
//停止文件下载 EK\xc'6M
public void siteStop() 3]7j,1^
{ vSCJ xSt#e
bStop = true; 8LY^>.
for(int i=0;i<nStartPos.length;i++) )d{fDwrx1
fileSplitterFetch.splitterStop(); [<jU$93E
F8\JL %
8RS@YO
} @R`Ao9n9V
} 0])[\O`j
//负责部分文件的抓取 8}Q2!,9Q
**FileSplitterFetch.java bH%d*
*/ {.Brh"yC
package NetFox; I:;umyRH
?0:=+%.
L3s"L.G
import java.io.*; d9l2mJzW
import java.net.*; XXXQAY-,C
vu:] [2"0
m.lzkS]P
public class FileSplitterFetch extends Thread { p]7IoO -@
iUZV-jl2/
H6lZ<R{=
String sURL; //File URL +.uQToqy
long nStartPos; //File Snippet Start Position VWk{?*Dp
long nEndPos; //File Snippet End Position f`[E^zj
int nThreadID; //Thread's ID iAt&927
boolean bDownOver = false; //Downing is over p ^)3p5w
boolean bStop = false; //Stop identical q-/t?m0
FileAccessI fileAccessI = null; //File Access interface t"vkd
w=5<mw
mgb+HNH%q\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tCv}+7)
{ F4IU2_CnPD
this.sURL = sURL; )`mBvS.}
this.nStartPos = nStart; Sf2xI'
this.nEndPos = nEnd; %Y9CZRY9
nThreadID = id; vX&W;&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /*t H$\6*
} gOm8 O,
{/qQ=$t
O.jCDAP
public void run() z:&/O&?
{ -Q|]C{r
while(nStartPos < nEndPos && !bStop) ~"8r=8|
{ RSnBG"
WS%yV|e
/0XmU@B
try{ ^zfs8]QSf
URL url = new URL(sURL); #K!"/,d@>J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )^ PWr^
httpConnection.setRequestProperty("User-Agent","NetFox"); I^[[*Bh*C
String sProperty = "bytes="+nStartPos+"-"; $<3^( y
httpConnection.setRequestProperty("RANGE",sProperty); ,}NTV~
Utility.log(sProperty); -wh
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4zZ.v"laVM
InputStream input = httpConnection.getInputStream(); x~](d8*=
//logResponseHead(httpConnection); Vd'=Fe;eB
Xv+,Z<>iQ
D2RvFlAXu
byte[] b = new byte[1024]; \m=k~Cf:f
int nRead; E;An':j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &q#. >
{ ^z51f>C
nStartPos += fileAccessI.write(b,0,nRead); ` }B,w-,io
//if(nThreadID == 1) ')Y1cO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e$&n)>%
} 5<P6PHdY
*U`R<mV\
AS'+p%(
Utility.log("Thread " + nThreadID + " is over!"); 8isQL
bDownOver = true; bCiyz+VyJn
//nPos = fileAccessI.write (b,0,nRead); *;U<b
} 4[)tO-v:Y
catch(Exception e){e.printStackTrace ();} 7`&6l+S|
} JEF;Q
} x~K79Mya
l hST%3Ld
+,j6dYub
//打印回应的头信息 IR8yE`(h
public void logResponseHead(HttpURLConnection con) 7y_<BCx h
{ \ _?d?:#RD
for(int i=1;;i++) T1'\!6_5
{ 5=R]1YI~$
String header=con.getHeaderFieldKey(i); GInw7
if(header!=null) ZZi|0dG4;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EK&0Cn3z
Utility.log(header+" : "+con.getHeaderField(header)); PKQ.gPu6*@
else "8~PfLJ+
break; ,H1K sN
} }F|B'[wn
} hE<Sm*HU
EV7lgKM^
&xp]9$
public void splitterStop() l=x(
{ /!qP=ngw9
bStop = true; 3[8p,wx
} C~C`K%7
X,{[R |
Av4(=}M}@
} ) $0>L5d:
mu5r4W47
HJP~ lg
/* |dDKO
**FileAccess.java ZT8LMPC
*//文件访问(定位，写) &9"Y:),
package NetFox; }6=? zs}
import java.io.*; t0Jqr)9}6
?Iq{6O>D.
4Z5;y[k(
public class FileAccessI implements Serializable{ V^rL
5=%KK3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iio-RT?!
RandomAccessFile oSavedFile; Kmw #Q`
long nPos; .Lu3LVS
*z.rOY= 8
}D.\2x(J
public FileAccessI() throws IOException X5)(,036
{ 9,JWi{lIv
this("",0); Et0)6^-v
} ;cZp$ xb3
cBv"d ~
z;ku*IV
public FileAccessI(String sName,long nPos) throws IOException _"*sx-
{ UtQCTNjC{
oSavedFile = new RandomAccessFile(sName,"rw"); zx*D)i5-
this.nPos = nPos; hljKBx~
oSavedFile.seek(nPos); _O;4>
} CGkx_E]
B^/k`h6J
o\; hF3
public synchronized int write(byte[] b,int nStart,int nLen) U<E]c 4*
{ Dwr 9}Z-]
int n = -1; Bf6i{`!G
try{ Nwe-7/Q
oSavedFile.write(b,nStart,nLen); 0s\ -iub=d
n = nLen; X8-x$07)
} ?~(#~3x
catch(IOException e) @|bJMi
{ mx UyD[|
e.printStackTrace (); /Ov1eQBNG
} R/kJUl6HEl
L#J2J$=
&`m$Zzl;
return n; `j!_tE`
} y7%SHYC p[
gVI`&W__,
%QEyvl4
} L]u^$=rI
P}qpy\/(4
_:WNk(
/* x+;y0`oL
**SiteInfoBean.java =N8_S$nx(
*/ FOsxId[f9
package NetFox; jA[Ir3
>EZZEd
-ZyY95E<
public class SiteInfoBean { ek]nLN
E@n~ @|10
lI+^}-<
private String sSiteURL; //Site's URL Nu\<Xr8
private String sFilePath; //Saved File's Path f-ceDn
private String sFileName; //Saved File's Name xSNGf@1b
private int nSplitter; //Count of Splited Downloading File c!'\k,ma<9
&I(\:|`o
?u/UV,";y
public SiteInfoBean() {?2|rv)
{//nSplitter的缺省值为5 'W>y v
//default value of nSplitter is 5 }L&LtW{X
this("","","",5); 3bR%#G%
} ^SKHYo`,,N
o4J@M{xb_
g_N^Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Jj5VBI!Ok
{ S~E@A.7
sSiteURL= sURL; { 0&l*@c&
sFilePath = sPath; <VutwtA
sFileName = sName; s{8=Q0^
this.nSplitter = nSpiltter; G--(Ef%v'
BV }CmU&DA
YOj&1ymBZ
} &/ED.K
RqP_^tB
RyG6_G}
public String getSSiteURL() B]:|;d
{ BzkfB:wr
return sSiteURL; F|qMo|
} DV[FZ
-mn/Yv
vy{k"W&S
public void setSSiteURL(String value) G%;>_E
{ '3Q~y"C+4
sSiteURL = value; D~URY_[A
} ey,f igjd.
f1+
VB#&`]rdo
public String getSFilePath() R! On
{ EP>Lh7E9n
return sFilePath; c@"FV,L>
} 4,Oa(b
<\O8D0.d
dJQK|/
public void setSFilePath(String value) W5= j&&|!
{ EhM=wfGKw
sFilePath = value; bgKC^Q/F
} FI.F6d)E$
-!\%##r7~
P=KhR&gwV~
public String getSFileName() x<Gjr}
{ *78c2`)[
return sFileName; m-ibS:
} UZrEFpi
O(!;7v}
#+V4<o
public void setSFileName(String value) cL~WDW/
{ -,T!/E
sFileName = value; V,0$mBYa
} dcD#!v\0
&rD8ng+$
D4|Ajeo;1
public int getNSplitter() /4 OmnE;
{ k ,+,,W
return nSplitter; 6 U[VoUU
} =~Qg(=U0U
zrG
VPuR4p.
public void setNSplitter(int nCount) naH(lz|v
{ %.r\P@7/Q
nSplitter = nCount; p9u*l
} A%HIfSzQBS
} /|P{t{^WM
k'H[aYMA
nKS*y*
/* *AQ3RA8
**Utility.java :[328X2
*/ ".$kOH_:
package NetFox; 'j, ([
0XCAnMVo
LjE3|+pJ
public class Utility { G?=&\fg_:
jll:Rh(b
,>7dIJqzw
public Utility() 3*2~#dh=
{ 9T5 F0?qd
~ZSX84~@u
LQ4:SV'3
} fW+"Kuw
{d;z3AB
//线程睡眠 IF|;;*Z8
public static void sleep(int nSecond) f<VK\%M
{ M!Ao!D[
try{ 0#eb] c
Thread.sleep(nSecond); [J}eNprg
} ?HZ^V
catch(Exception e) WPNw")t!
{ WQ[nK5#
e.printStackTrace (); =FV(m S
} tlUh8os
} 7<MEMNYX
d94k
//日志 D:bmq93PC
public static void log(String sMsg) gDLS)4^w
{ EJTM >Rpor
System.err.println(sMsg); nb=mY&q}~
} 6)*fr'P
.!0Rh9yyl
9?O8j1F
public static void log(int sMsg) 4s9@4
{ + c3pe4
System.err.println(sMsg); *->*p35
} mHW%:a\L
} Gt*K:KT=L
0Atha>w^o~
h+j^VsP zB
/* z{\tn.67
**TestMethod.java `14@dk
*/ }BI6dZ~2A
package NetFox; y,|2hrj/0E
s9CmR]C
W-#DEU 7_
public class TestMethod { wzju)qS
XF)N_}X^
6d;}mhH
public TestMethod() Bt}90#
{ ///xx/weblogic60b2_win.exe cpP}NJb0;%
try{ S9}I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P4_B.5rrJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d9k`
SiteFileFetch fileFetch = new SiteFileFetch(bean); v9Ii8{ca|
fileFetch.start(); pMHl<HH
} \zg R]|
catch(Exception e){e.printStackTrace ();} 9]lI?j]o
6_QAE6A
~&T U
} iD|~$<9o
'%ilF1#
\u[}
public static void main(String[] args) HYGd :SeH
{ p:y\{k"
new TestMethod(); =O0A(ca"g
} }RadbJ{q=
} RVwS<g)~1
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