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)); QEz?w}b*
} dIN$)?aB0
for(int i=0;i<nEndPos.length-1;i++) {1UQ/_
{ F5P[dp-`1
nEndPos = nStartPos[i+1]; -w9pwB
} Q.l}NtHwV
nEndPos[nEndPos.length-1] = nFileLength; uJzG|$;
} TW)c#P43K
} (s.0PO`
c6h.iBJ'
QRHu3w
//启动子线程 {:6r;TB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; % tS,}ze
for(int i=0;i<nStartPos.length;i++) /t+f{VX$
{ o /j*d3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (;T^8mI2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :r{<zd>;
nStartPos,nEndPos,i); h2Ld[xvCu%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 11o.c;
fileSplitterFetch.start(); vdAr|4^qB
} #|L8tuWW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +R3k-' >
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 39:bzUIF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?9e_gV{&;
nEndPos = " + nFileLength); O_`VV*
// fileSplitterFetch[nPos.length-1].start(); 1eS&&J5
IpYM;tYw&
pMw*9sX
//等待子线程结束 IwQ"eUnK
//int count = 0; eD,.~Y#?=
//是否结束while循环 _zY#U9
boolean breakWhile = false; &dqLP95
C _'%NlJ'
.+PI}[g
while(!bStop) u+Y\6~=+
{ %|auAq&w
write_nPos(); fObg3S92
Utility.sleep(500); v- 2:(IV
breakWhile = true; `=4r+
e>6y%v;
dBYmiF!+
for(int i=0;i<nStartPos.length;i++) wjHzE
{ g%sluT[#
if(!fileSplitterFetch.bDownOver) C'9Cr}cZ.
{ arIf'CG6
breakWhile = false; a=J^
break; uxXBEq;
} J%u=Ucdh
} BF\XEm?!
if(breakWhile) )(bW#-
break; h;p>o75O
<c2E'U)X
MI/MhkS ?
//count++; 94h]~GqNi
//if(count>4) &v56#lG
// siteStop(); [4YTDEv%
} >"^ O"E
Nv#t:J9f
;Y00TGU
System.err.println("文件下载结束！"); LhA*F[6$M
} (up~[
catch(Exception e){e.printStackTrace ();} w mn+
} %'bM){
/a{la8Ni
* aN
//获得文件长度 9+j0q%
public long getFileSize() YN/|$sMD|
{ &Y!-%{e
int nFileLength = -1; IdzxS
try{ v:IpMU-+\
URL url = new URL(siteInfoBean.getSSiteURL()); WffQ:L?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &-;4.op
httpConnection.setRequestProperty("User-Agent","NetFox"); zNs55e.rx
xcd#&
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int responseCode=httpConnection.getResponseCode(); X3{G:H0\p
if(responseCode>=400) yQU{zY
{ .CL[_;}
processErrorCode(responseCode); QA< Rhv,
return -2; //-2 represent access is error Z/W:97M
} =#;3Q~:Jl^
\K5DOM "#
nL5cK:
String sHeader; CuFSeRe
UbXh,QEG*
{&cJDqz5=
for(int i=1;;i++) pV9IHs}
{ &q3"g*q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FEW14U'O
//Utility.log(in.readLine()); '9laa=H%8
sHeader=httpConnection.getHeaderFieldKey(i); fa-IhB1!K
if(sHeader!=null) qB~rQPa
{ ,kiv>{
if(sHeader.equals("Content-Length")) y`VyQWW
{ IoxgjUa
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I5`4Al
break; L5Ebc#
} SzAJ2:qhl
} ! +a.Ei
else y=fx%~<> 8
break; G/k2Pe{SL
} vleS2-]|
} XeW<B0~
catch(IOException e){e.printStackTrace ();} !<j'Ea
catch(Exception e){e.printStackTrace ();} |nc@"OJ
%>yG+Od5Z
w^?>e;/\
Utility.log(nFileLength); /$ w%Q-p
n&L+wqJ
4;w;'3zq
return nFileLength; sQ=]NF)\
} hB"fhX
tWJZoD6}h
P60~V"/P
//保存下载信息（文件指针位置） 2V"B:X\
private void write_nPos() v:f}XK<
{ ]%hn`ZJ
try{ s6H]J{1F
output = new DataOutputStream(new FileOutputStream(tmpFile)); RM]\+BK
output.writeInt(nStartPos.length); fFMlDg[];
for(int i=0;i<nStartPos.length;i++) 2L:_rR#w
{ `[z<4"Os
// output.writeLong(nPos); KT_!d*
output.writeLong(fileSplitterFetch.nStartPos); SOs:]U-T3
output.writeLong(fileSplitterFetch.nEndPos); SbND Y{5RO
} !F*5M1Kjd
output.close(); c'^?/$H|
} wu7Lk3
catch(IOException e){e.printStackTrace ();} srPWE^&
catch(Exception e){e.printStackTrace ();} VEH&&@d
} xmNB29#
<C_jF
w;;BSJ]+[
//读取保存的下载信息（文件指针位置） c>,'Y)8
private void read_nPos() @GPCwE1
{ o@r7 n>G
try{ Hn7_FOC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mz9r5
int nCount = input.readInt(); ~xbe~$$Q@
nStartPos = new long[nCount]; 3]OE}[R
nEndPos = new long[nCount]; &#o~U$GBg
for(int i=0;i<nStartPos.length;i++) H7?Vybg~
{ ++bf#qS<8D
nStartPos = input.readLong(); v6[!o<@"a
nEndPos = input.readLong(); c%^7!FSg
} 7G:s2432
input.close(); AhCW'.
} g9m-TkNk
catch(IOException e){e.printStackTrace ();} 4qphA9i1
catch(Exception e){e.printStackTrace ();} h(<,fg1
} /vY(o1o x
_- [''(E
o906/5M
private void processErrorCode(int nErrorCode) qPWP&k
{ }HL]yDO
System.err.println("Error Code : " + nErrorCode); 9"@\s$ OBk
} q YC;cKv
#=D) j
dl.N.P7}4
//停止文件下载 dah[:rP,n{
public void siteStop() b1?#81
{ teOe#*
bStop = true; s6ZuM/Q
for(int i=0;i<nStartPos.length;i++) jG6]A"pr
fileSplitterFetch.splitterStop(); H ;7(}:.
@D)al^]x6
b}OY4~ Y4
} ~9?cn
} Av @b!iw+
//负责部分文件的抓取 Y_Eb'*PY
**FileSplitterFetch.java d4m=0G`
*/ .0p0_f=
package NetFox; ZWii)0'PV
t#yk->,
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import java.io.*; NWP5If|'X
import java.net.*; LnFdhrB@x
7WZrSC
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public class FileSplitterFetch extends Thread { jLy
tN[L@t9#cr
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String sURL; //File URL #mlS}~n
long nStartPos; //File Snippet Start Position x"eRJii?
long nEndPos; //File Snippet End Position Xk:OL,c
int nThreadID; //Thread's ID _G_Cj{w
boolean bDownOver = false; //Downing is over lackB2J9 A
boolean bStop = false; //Stop identical ?42<J%p
FileAccessI fileAccessI = null; //File Access interface zuP B6W^
*aXF5S
>@BnV{ d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,V'o4]H
{ ,4hJT
this.sURL = sURL; 32l3vv.j
this.nStartPos = nStart; ImCe K
this.nEndPos = nEnd; iy6On,UL
nThreadID = id; 2^XGGB0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7;u e
} 4)E_0.C
#w;v0&p
rI{=WPI&WU
public void run() "B8Q:
{ TbA}BFT`
while(nStartPos < nEndPos && !bStop) D,m]CK'
{ ;1#H62Z*
c@YI;HS_g
5Y?L>QU"
try{ *v?`<)P#
URL url = new URL(sURL); du+y5dw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k2E0/ @f{k
httpConnection.setRequestProperty("User-Agent","NetFox"); zFfoqb#*g
String sProperty = "bytes="+nStartPos+"-"; R= a|Blp
httpConnection.setRequestProperty("RANGE",sProperty); liEPCWl&
Utility.log(sProperty); O[# 27_dH
d[r#-h>dS
kTKq/G,Ft
InputStream input = httpConnection.getInputStream(); 01[NX? qEa
//logResponseHead(httpConnection); :Y-{Kn6`_
}p=Jm)y
,?PTcQF
byte[] b = new byte[1024]; Wi>!{.}%A
int nRead; M]<?k]_p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U2$d%8G
{ |\w=u6jX
nStartPos += fileAccessI.write(b,0,nRead); ^*S ,xP
//if(nThreadID == 1) wU8Mt#D!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ADZ};:]
} ~a%Z;Aj
BNz5lrfq
jNe`;o
Utility.log("Thread " + nThreadID + " is over!"); Kfm5i Q
bDownOver = true; F8hw#!Aq
//nPos = fileAccessI.write (b,0,nRead); XttqOf
} KuWWUjCE
catch(Exception e){e.printStackTrace ();} h a|C&G
} n-5W*zk1
} 'AzDP;6qFI
Y_}mYvJW
uB |Ss
//打印回应的头信息 |}23>l7
public void logResponseHead(HttpURLConnection con) `(T,+T4C5k
{ v. %R}Pa
for(int i=1;;i++) Xf0M:\w=M
{ jQk*8
String header=con.getHeaderFieldKey(i); Z1zVwHa_
if(header!=null) `J]fcE%T0R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ttXXy3G#
Utility.log(header+" : "+con.getHeaderField(header)); 9F6F~::l}
else Hip&8NW
break; L93l0eEt
} BLN^ <X/
} %509\;el
V7#Ffi
6W@UJx}w5
public void splitterStop() '[J<=2&
{ Nb?w|Ne(T
bStop = true; YiYV>gaf"H
} vK(i9>;7
lW<PoT
|4 v0:ETb$
} AGH|"EWG
+$X#q8j06
!) S ?m
/* ~n[d4qV&
**FileAccess.java CQZgMY1{
*//文件访问(定位，写) Mmj;'iYOwF
package NetFox; Y^36>1.:
import java.io.*; K6y :mJYp\
+${D
6Z#\CixG
public class FileAccessI implements Serializable{ $f,n8]
Sa\!*e_sN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f?oa"
RandomAccessFile oSavedFile; dp++%:j
long nPos; qZ]pq2G
|"XPp!_uN
:]rJGgK#
public FileAccessI() throws IOException 3VI4X
{ Q s.pGi0W
this("",0); df*5,NV'-*
} iQ4);du
H(2!1?N+
".SJ~`S
public FileAccessI(String sName,long nPos) throws IOException ;GVV~.7/
{ $jm>:YD
oSavedFile = new RandomAccessFile(sName,"rw"); xO1[>W
this.nPos = nPos; #Pw2Q
oSavedFile.seek(nPos); bgS${n/
} Kk(9O06j
j>]nK~[ka
kgy:Q'
public synchronized int write(byte[] b,int nStart,int nLen) 4VHqBQ4
{ ;^La"m
int n = -1; xBUya4w
try{ HODz*pI
oSavedFile.write(b,nStart,nLen); kxp);
n = nLen; 0E?jW7yr
} YhbZ'SJ
catch(IOException e) *\(r+>*x*
{ -6Oz^
e.printStackTrace (); 6&DX] [G
} i O/K nH
4Y,R-+f
_2k]3z?
return n; O$D'.t
} zS\E/.X2
n8uv#DsdK
I&MY{f
} a\IP12F?
*5 |)-E
u)3 $~m~
/* &=<x#h-
**SiteInfoBean.java !_+8A/
*/ 8~9030>Q
package NetFox; @Ukr
<c)+Fno[E_
F6o_b4l
public class SiteInfoBean { uHH/rMV
XO-Prs
'\Jj8oJQj
private String sSiteURL; //Site's URL B.g[c97
private String sFilePath; //Saved File's Path y_*PQZ$c<
private String sFileName; //Saved File's Name #O$
private int nSplitter; //Count of Splited Downloading File AX?fuDLs
I8+~ &V}
[cTe54n
public SiteInfoBean() %STliJ
{//nSplitter的缺省值为5 %|^OOU}
//default value of nSplitter is 5 )x}l3\s
this("","","",5); *<E]E?
} 'xhcuVl
d)@<W1;
G P:FSprP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?."&MZ
{ $U$V?xuE
sSiteURL= sURL; |+35y_i6
sFilePath = sPath; z\0CE]#T
sFileName = sName; tp6M=MC%
this.nSplitter = nSpiltter; eh4gQ^l
N=5)fe%{4
hty0Rb[dH
} XYS'.6k(
aFe`_cnG
{K4+6p
public String getSSiteURL() JYrY[',u
{ [q_`X~3
return sSiteURL; txZ?=8j_Y
} neXeAU
-zp0S*iP7
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public void setSSiteURL(String value) VtzI9CD
{ vKq^D(&cl
sSiteURL = value; |o2sbLp
} 7_.11$E=H
,g7.rEA
a-"k/P#
public String getSFilePath() "V>R9dO{"!
{ Cw~RJ^a_
return sFilePath; cTXri8K_
} `((Yc]:7
G0`h%
#l4)HV
public void setSFilePath(String value) Kx.X7R
{ MZpK~c1`
sFilePath = value; aM@z^<Ub
} FuUD 61JHY
6*qL[m.F[o
y kW [B
public String getSFileName() :9R=]#uD
{ HJ2*y|u
return sFileName; 21ppSN>
} }w/;){gu
G [:N0{v5
|y h\
public void setSFileName(String value) xXY.AoO6
{ }R)=S_j
sFileName = value; i.xXb[M+
} $xOI 1|d
9%iUG(DC
`C_jP|[e
public int getNSplitter() BnCKSg7V
{ ed!:/+3e/
return nSplitter; >6~k9>nDb<
} RrhT'':[
:d0Y%vl
/wxE1][.
public void setNSplitter(int nCount) hY*0aZ|(
{ &n[~!%(
nSplitter = nCount; i\4hR?
} KJ?y@Q
} mAeuw7Ni
.fi/I
L>!8YUz7p$
/* TDg@Tg0
**Utility.java :qR=>n=
*/ ]Ni;w]KE
package NetFox; `/"nTB
jYVE8Y)my
iJv48#'ii
public class Utility { xrqv@/kJ
jSOS}!=
F,GN[f-
public Utility() 4D$;KokZ
{ g|Y] wd
O<jPGU
{/LZcz[
} 9'DtaTmGW
fa&-. *
//线程睡眠 /({;0I*!i
public static void sleep(int nSecond) B_ja&) !s1
{ .}k(L4T|=
try{ nx:KoB"ny
Thread.sleep(nSecond); FP#FB$eP
} .lBgp=!
catch(Exception e) !)qQbk
{ 4Hb $0l
e.printStackTrace (); aup6?'G;
} dI*'!wK
} DY{cQb
e,k2vp!<&
//日志 W%e_~$H0
public static void log(String sMsg) Sf/q2/r?6[
{ x|0:P sE
System.err.println(sMsg); #5&jt@NS
} .fzu"XAPu
cBYfXI0`
Eq^uKi
public static void log(int sMsg) v8/6wy?
{ `W `0Fwu9
System.err.println(sMsg); 3ta$L"a
} mPPk)qy
} ~=&t0D
85IMdZ7I
]~>K\i
/* Ch_xyuJ
**TestMethod.java _P,^_%}V06
*/ Te{ *6-gO3
package NetFox; BHj\G7,S
B|%tE{F
02JoA+
public class TestMethod { V (rr"K+
g,]@4|
"PH6e bm
public TestMethod() -6=<#9R
{ ///xx/weblogic60b2_win.exe )9=(|Lp
try{ `@`1pOb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2 ?|gnbE:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0_yP\m
SiteFileFetch fileFetch = new SiteFileFetch(bean); XM|%^ry
fileFetch.start(); G",.,Px
} K?u(1
catch(Exception e){e.printStackTrace ();} +m,!e*g
?@R")$
p|XAlia
} 8I+d)(:
g):]'
]Z4zF"@
public static void main(String[] args) -Dzsa
{ f+Dn9t
new TestMethod(); w7-WUvxl
} XD-^w_
} ,xths3.K
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