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)); D$vP&7pOr4
} fN-y8
for(int i=0;i<nEndPos.length-1;i++) XVRtfo
{ V1 :aR3*!
nEndPos = nStartPos[i+1]; B|zVq=l~
} W4ygJL7 6
nEndPos[nEndPos.length-1] = nFileLength; qbunP!
} -gzY~a
} mKh<M)Bz
F VVpyB|
xtN=?WjVe0
//启动子线程 * SHQ[L4{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B+pJWl8u
for(int i=0;i<nStartPos.length;i++) Kd%>:E*
{ l4LowV7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U*R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uTq)Ets3
nStartPos,nEndPos,i); &l| :1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ->0OqVQA
fileSplitterFetch.start(); a=%QckR*
} n~e#Y<IP\1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NW*qw q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (r!d4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NU#rv%p
nEndPos = " + nFileLength); j\^u_D
// fileSplitterFetch[nPos.length-1].start(); 1(ud(8?|
=#Qm D=
a#NP69
//等待子线程结束 Jemb0Qv
//int count = 0; Z^?YTykH
//是否结束while循环 >RL|W}tI4
boolean breakWhile = false; /U1 jCLR'
xy.di9
,TdL-a5
while(!bStop) w*-1*XNA
{ 1$^=M[v
write_nPos(); puPYM"
Utility.sleep(500); J@4,@+X
breakWhile = true; HbUadPr
`tjH#W`
xSal=a;k
for(int i=0;i<nStartPos.length;i++) ROfr
{ wsg u# as|
if(!fileSplitterFetch.bDownOver) cz6\qSh\,
{ F87aIJ.pGN
breakWhile = false; w]Fi:kV
break; 4[$D3,A
} fmv8)$W#U
} GSh~j-C'
if(breakWhile) zV<vwIUrr
break; Dqu][~oQ
LmA IvEr
1X45~
//count++; MGGc
//if(count>4) e52y}'L
// siteStop(); $sTvXf:g
} 4CdST3
|n_es)A
^^m3 11=
System.err.println("文件下载结束！"); k"V@9q;*
} #VA8a=t
catch(Exception e){e.printStackTrace ();} *G,'V,?
} z#|#Cq`VG
ncy?w e
uSRvc0R\
//获得文件长度 'J=knjAT
public long getFileSize() CaV>\E)
{ UVIR P#
int nFileLength = -1; +#/`4EnI
try{ my|UlZ(qg
URL url = new URL(siteInfoBean.getSSiteURL()); )U':NV2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fsxZQ=-PW
httpConnection.setRequestProperty("User-Agent","NetFox"); bR*/d-v^
jRv j:H9
xqAXfJ.
int responseCode=httpConnection.getResponseCode(); ~1`ZPLVG
if(responseCode>=400) FlPPz
{ 5Tt%<#4
processErrorCode(responseCode); o3oAk10
return -2; //-2 represent access is error YV 5kzq
} t;~H6
E{-W#}#
fcC?1M[BP~
String sHeader; "++q.y
*k7vm%#ns
; {P"~(S%
for(int i=1;;i++) 1 =cFV'
{ PilV5Gg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %N, P? ,U
//Utility.log(in.readLine()); wv~?<DF
sHeader=httpConnection.getHeaderFieldKey(i); yye(^
if(sHeader!=null) )ZI9n7
{ r,`59
if(sHeader.equals("Content-Length")) tluyx
{ '[6o(~*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @fVCGV?'
break; {m&8Viq1
} I'NE>!=Q
} 2EdKxw3$]
else ^6Std x_
break; t#p*{S 3u
} hjgxCSp
} l*yh(3~}
catch(IOException e){e.printStackTrace ();} V(Dn!Nz
catch(Exception e){e.printStackTrace ();} >;;tX3(
#n[1%8l,
Yp_R+a^
Utility.log(nFileLength); ppBIl6
7JedS
m#(tBfH[
return nFileLength; e0#/3$\aSV
} 2[*r9%W
VS:UVe
cVR3_e{&H
//保存下载信息（文件指针位置） OEkx}.w
private void write_nPos() aC&ZV}8of
{ l/JE}Eg(
try{ zMXlLRC0
output = new DataOutputStream(new FileOutputStream(tmpFile)); l u^fKQ
output.writeInt(nStartPos.length); 9J$8=UuxWG
for(int i=0;i<nStartPos.length;i++) J01Y%W
{ #e!4njdM
// output.writeLong(nPos); ;I#S m;
output.writeLong(fileSplitterFetch.nStartPos); x 7;Zwd
output.writeLong(fileSplitterFetch.nEndPos); y,*>+xk,
} bYKyR}e
output.close(); f.o,VVYi
} 7sQw&yUL)
catch(IOException e){e.printStackTrace ();} B~0L'8WzW
catch(Exception e){e.printStackTrace ();} \I"UW1)B
} 5nGDt~a
]vPa A
Au6*hv3:
//读取保存的下载信息（文件指针位置） n>w/T"
private void read_nPos() r*'X]q|L+
{ 6G<t1?_yD
try{ ::xH C4tw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D{](5?$`|
int nCount = input.readInt(); f|*vWHSM
nStartPos = new long[nCount]; @R|Gz/
nEndPos = new long[nCount]; +n ${6/
for(int i=0;i<nStartPos.length;i++) T/_JXK>W
{ 9\/T #EP
nStartPos = input.readLong(); ,u^S(vxyz
nEndPos = input.readLong(); V0gk8wD
} s{-`y`JP
input.close(); aN.t) DG}J
} {ZS-]|Kx
catch(IOException e){e.printStackTrace ();} L29,Y=n@
catch(Exception e){e.printStackTrace ();} Vs1j9P|G
} hm%'k~
2>.2H
R|%R-J]
private void processErrorCode(int nErrorCode) Y=oj0(Q*
{ z|Hc=AU8y
System.err.println("Error Code : " + nErrorCode); .oJs"=h:m
} \;?=h
H(^O{JC]y!
rpgr5>
//停止文件下载 5dVSir
public void siteStop() ?/_8zpW
{ 0,T'z,
bStop = true; iI[Z|"a21
for(int i=0;i<nStartPos.length;i++) >@yHa'*9S
fileSplitterFetch.splitterStop(); 3&D;V;ON}_
m[7i<'+S
IeqJ>t:
} IX7|_ci
} -$(,&qyk
//负责部分文件的抓取 ) #/@Jo2F
**FileSplitterFetch.java ({ 7tp!@
*/ DRo@gYDn
package NetFox; |\ 1?CYx
9E (VU.
C^@.GA
import java.io.*; .EC/[fM
import java.net.*; xg}RpC!
wl{Fx+<^3
U}xQUFT|
public class FileSplitterFetch extends Thread { ?"p:6%GFz
=?`5n|A*
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String sURL; //File URL SWjOJjn
long nStartPos; //File Snippet Start Position OQ$77]XtvL
long nEndPos; //File Snippet End Position Jlw oSe:S
int nThreadID; //Thread's ID wX6VapFboI
boolean bDownOver = false; //Downing is over lD!o4ZAo
boolean bStop = false; //Stop identical $X%GzrN
FileAccessI fileAccessI = null; //File Access interface 1n! JfsU
APT'2-I_
AW8"@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P!C!E/Jf5
{ x@F"ZiYD@O
this.sURL = sURL; G 1{F_
this.nStartPos = nStart; @L%9NqE`O
this.nEndPos = nEnd; R|T_9/#)
nThreadID = id; Gd)@PWK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BJ3st
} +igFIoHTM
td@F%*
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public void run() X[8m76/V
{ E'=~<&
while(nStartPos < nEndPos && !bStop) <^&NA<2
{ kb?QQ\e
fW Vd[zuD4
VT1W#@`e-
try{ Ox"4 y
URL url = new URL(sURL); ?aInn:FE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +]Oq{v:e
httpConnection.setRequestProperty("User-Agent","NetFox"); Q)}sX6TB
String sProperty = "bytes="+nStartPos+"-"; W'\{8&:!
httpConnection.setRequestProperty("RANGE",sProperty); cLH|;
Utility.log(sProperty); Bv$;yR
tw8@&8"
[R j=k)aBm
InputStream input = httpConnection.getInputStream(); <CL0@?*i9
//logResponseHead(httpConnection); @]Ye36v0#L
hu-fwBK
byM/LE7)
byte[] b = new byte[1024]; rUkiwqr~E
int nRead; Y%$57,Bu n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EA4aZ6%
{ m,3?*0BMp=
nStartPos += fileAccessI.write(b,0,nRead); >9D=PnHnD
//if(nThreadID == 1) 1Y410-.3w{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g2 uc+p
} x%ZjGDFm
"sz)~Q'W5
dL>0"UN}-
Utility.log("Thread " + nThreadID + " is over!"); z3b8
bDownOver = true; }io9Hk>|
//nPos = fileAccessI.write (b,0,nRead); |b'fp1</
} n{pS+u z
catch(Exception e){e.printStackTrace ();} ~130"WQ;
} !3K6ew>Sf
} OqDLb
x+(h#+F
Z>Nr"7k
//打印回应的头信息 De[!^/f;T
public void logResponseHead(HttpURLConnection con) y";{k+
{ pi? q<p%
for(int i=1;;i++) 8^;[c
{ )`Tny]M
String header=con.getHeaderFieldKey(i); .:c^G[CQ^9
if(header!=null) 7|3Z+#|T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ):eX*
Utility.log(header+" : "+con.getHeaderField(header)); in-/
else 8ON$M=Ze$
break; Oh<[8S7]C
} RNuOwZ1m
} ;Gxp'y
H$Fz{[[u
IuTZ2~
public void splitterStop() cS,(HLO91
{ H"d.yZM0
bStop = true; zt!mx{l'
} .@.,D% 7<
?<,9X06dP
?3Wh.%n
} -yOrNir}W
.hlr)gF&)
VB*$lxX
/* zl46E~"]x
**FileAccess.java y[S5
*//文件访问(定位，写) UDV,co
package NetFox; 2(LS<HqP[
import java.io.*; NFPW#-TF
@!^c@
MuYr?1<q
public class FileAccessI implements Serializable{ =jip* E^
,JRYG<O_T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -]\%a=]
RandomAccessFile oSavedFile; L.lmbxn
long nPos; R3wK@D
X!,P] G
!Pt|Hk dr
public FileAccessI() throws IOException }S3m wp<Y
{ ^-PlTmT
this("",0); (w?@qs!
} ^~|P[}
gSK (BP|
+60zJ4
public FileAccessI(String sName,long nPos) throws IOException a3ve%b
{ Skl1%`
oSavedFile = new RandomAccessFile(sName,"rw"); '@RlKMnN
this.nPos = nPos; / O6n[qj|
oSavedFile.seek(nPos); z}yntY]n
} c*K-?n9YMz
-ZH]i}$
3zY"9KUN
public synchronized int write(byte[] b,int nStart,int nLen) ?s#DD,
{ "P.7FD
int n = -1; {w}PV5<
try{ ,\4@Ao
oSavedFile.write(b,nStart,nLen); \TkBV?W
n = nLen; pNr3u
} I5>HB;Q
catch(IOException e) W}+Q!T=
{ ]K?z|&N|HK
e.printStackTrace (); 4vPQuk!
} a*6x^R;)
+Vt@~Z4K
O*rKV2\
return n; rPkV=9ull,
} bV|:MW<Wv
<_8\}!
y _>HQs,:
} ;2@MPx
{-J/ <a@
Wk$[;>NU3
/* tx Lo=
**SiteInfoBean.java KnbT2
*/ _;W}_p}q{
package NetFox; m*|3
2sjV*\Udf
'y}l9alF
public class SiteInfoBean { xKEHNgen
tn+i5Eso
*5sr\b4#S
private String sSiteURL; //Site's URL 1Jc-hrN-
private String sFilePath; //Saved File's Path g&O%qX-
private String sFileName; //Saved File's Name 5R?iTB1,
private int nSplitter; //Count of Splited Downloading File 20d[\P(.
Sb>;k(;`:
.1.n{4z>:
public SiteInfoBean() 0vQ@n7
{//nSplitter的缺省值为5 GfD!Z3
//default value of nSplitter is 5 pY!@w0.
this("","","",5); v)!Rir5
} nORm7sa9
XBUO
r75,mX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {6~v oVkj
{ c_x6FoE;L
sSiteURL= sURL; F'*y2FC
sFilePath = sPath; ;gTdiwfgZ=
sFileName = sName; <tMiI)0%
this.nSplitter = nSpiltter; #q9jFW8
zPWG^
K SDo)7`
} ^F5[2<O/!
aRdk^|}
r^n%PH<
public String getSSiteURL() ]Hc`<P
{ k+'Rh'>
return sSiteURL; YDyOhv
} .d^8w97
&sh %]o8
}ARWR.7Cc
public void setSSiteURL(String value) #n]js7
{ uNxR#S
sSiteURL = value; xV}E3Yj2#
} \,!FL))yC
29z+<?K{
-@Mr!!t?N
public String getSFilePath() fBR,Oneo
{ lV]hjt-L 2
return sFilePath; lJpD>\$}@R
} ~zi6wu(3
8TD:~ee
;iy]mPd
public void setSFilePath(String value) 73A1+2
{ l6:k|hrm;
sFilePath = value; %L=roqz
} _' Xt
R4 ;^R
u^s{r`/
public String getSFileName() =&U JFu
{ NYM$0v`0YK
return sFileName; $fPf/yQmC
} ,6~c0]/
_]E"hr6a
K8XXO"
public void setSFileName(String value) ;}#tm9S;
{ 8OqG{jmG
sFileName = value; n AQB
} <@.f#
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,oT?-PC$z
public int getNSplitter() LUna stA^
{ Vx;f/CH3!
return nSplitter; MIub^ $<C
} .!\y<9
1RY}mq
_FeLSk.
public void setNSplitter(int nCount) 4>uz'j<
{ oil s;*q
nSplitter = nCount; ) 2wof(
} xop9*Z$
} &dp(CH<De
1u:OzyJy
# 5v 2`|)
/* >(ku*
**Utility.java T?N' k=
*/ "(F>?pq
package NetFox; 8wp)aGTcU
/i"vEI
,+3l9FuQ
public class Utility { KRd.Ubs -
lRi-?I|~9
)a.w4dH
public Utility() {# ;e{v
{ e-sMU
_M8Q%
!`hiXDk*2
} gG1%.q
>M<rr!|
//线程睡眠 Q1mz~r
public static void sleep(int nSecond) d!{,[8&
{ &[`p qX
try{ Vl5}m
Thread.sleep(nSecond); 9w[7X"#n
} lsCD%P
catch(Exception e) wA|m/SZx
{ 0R\lm<&
e.printStackTrace (); k?0yH$)'t
} .n[!3X|d
} kLU$8L
XE[~! >'
//日志 {wih)XNY
public static void log(String sMsg) =>-:o:Cu{
{ j+\I4oFN
System.err.println(sMsg); ?w`uv9NUJ8
} EjV,&7o)
iIA5ylf{E
dms R>Q
public static void log(int sMsg) ..UmbJJ.u
{ tu#VZAPW@
System.err.println(sMsg); ),v[.9!}:
} wQgW9546
} j#$ R.
vQ2kL`@
AYeA)jk
/* 51W\%aB
**TestMethod.java &s->,-,
*/ 2>l4$G0
package NetFox; dX-{75o5P
{1li3K&0s
" |[w.`
public class TestMethod { F<Js"z+
cW4:eh
0(VAmb%{
public TestMethod() GKu@8Ol-wu
{ ///xx/weblogic60b2_win.exe &Ey5 H?U!
try{ -'QvUHL|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ac0C,*|^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?wt%e;
SiteFileFetch fileFetch = new SiteFileFetch(bean); @(Wx(3JR?}
fileFetch.start(); @G+Hrd6
} r"d/9
catch(Exception e){e.printStackTrace ();} [wWip1OR
coT|t T
w&jyijk(
} =hxj B*")
;XNe:g.CR
+[:"$?J
public static void main(String[] args) Qz2Yw `
{ !4\`g?
new TestMethod(); Eqc&iS~
} TCYjj:/
} -lV]((I&
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