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)); O$7cN\Z
} zSagsH |W
for(int i=0;i<nEndPos.length-1;i++) *Ksk1T+>
{ %)w7t[A2D
nEndPos = nStartPos[i+1]; AAF']z<4_"
} B:VGa<lx5
nEndPos[nEndPos.length-1] = nFileLength; ](^FGz
} &S39SV
} H6hhU'Kxf8
9\VV++}s>o
>mj WC) U
//启动子线程 d*dPi^JjC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7l4}b^>/`
for(int i=0;i<nStartPos.length;i++) QIfP%,LT
{ 88VI _<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /*(&Dmt>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jN!VrRA
nStartPos,nEndPos,i); jdkqJ4&i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %6la@i
fileSplitterFetch.start(); u s8.nL/
} nG%<n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )4RSo&9p`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p2 !w86 F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >*EJ6FPO
nEndPos = " + nFileLength); gnadx52FP
// fileSplitterFetch[nPos.length-1].start(); X!6$<8+1OV
deEc;IAo
JfRLqA/
//等待子线程结束 ?DE{4Ti/[
//int count = 0; Myf2"\}
//是否结束while循环 ,0eXg
boolean breakWhile = false; q ,+29
; o(:}d
IdCE<Oj\
while(!bStop) R[l~E![!j
{ uR.`8s|
write_nPos(); 4|UtE<<b
Utility.sleep(500); &\ K
breakWhile = true; }L @~!=q*
Bkg./iP5x
-b)3+#f
for(int i=0;i<nStartPos.length;i++) `7oYXk
{ /m4Y87
if(!fileSplitterFetch.bDownOver) a1EQ.u
{ w~3z);
breakWhile = false; "5v^6R9e
break; @O|`r(le
} :`c@&WF8
} ,u9>c*Ss\
if(breakWhile) })j N 8px
break; <B'PB"R3y
+UiJWO
= toU?:.
//count++; )6%a9&~H
//if(count>4) (+}44Ldt
// siteStop(); NZ?dJ"eq7
} UgD)O:xaU
^\r{72!y
@k\,XV`T~t
System.err.println("文件下载结束！"); wRZS+^hx
} 'wWuR@e#&
catch(Exception e){e.printStackTrace ();} hxt;sQAo{
} xEv?2n@A
Cq[Hh#q
4ves|pLET
//获得文件长度 j=c< Lo`
public long getFileSize() $W9dUR0
{ Ya-GDB;L
int nFileLength = -1; LYiIJAZ.
try{ D~M*]&
URL url = new URL(siteInfoBean.getSSiteURL()); |E;+j\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0U !&|i\
httpConnection.setRequestProperty("User-Agent","NetFox"); -j@IDd7
GiKhdy
""m/?TZq'
int responseCode=httpConnection.getResponseCode(); ~%h&ELSw
if(responseCode>=400) J ~KygQ3%
{ !%B-y9\
processErrorCode(responseCode); oi8M6l
return -2; //-2 represent access is error ge1U1o
} ce*?crOV
Kw2]J)TO
L* ScSxw
String sHeader; p.H`lbVY
$j\jT
]=59_bkD:s
for(int i=1;;i++) "1`w>(=
{ %-BwK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yZ]?-7
//Utility.log(in.readLine()); [[xnp;-;
sHeader=httpConnection.getHeaderFieldKey(i); I:0dz:T7*
if(sHeader!=null) a-AA$U9hj
{ *$3p3-
if(sHeader.equals("Content-Length")) V{~~8b1E
{ c7R&/JV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z2Z}mktP
break; m_FTg)_=
} 93ggCOaYA
} c[$i)\0
else *_]fe&s=%
break; $.31<@T7
} 'v=BAY=Ef
} r%>EiHpCU
catch(IOException e){e.printStackTrace ();} vu&ny&=`
catch(Exception e){e.printStackTrace ();} l<'}`
$`R=Q
Vy^mEsQC+h
Utility.log(nFileLength); @1U6sQ
[z6P]eC7
:Zo^Uc:*w
return nFileLength; eu?P6>urA
} {Z1-B60P
g|h;*
rB|4
//保存下载信息（文件指针位置） %NfH`%`
private void write_nPos() !& >LLZ
{ r{_1M>F D!
try{ >GzH_]
output = new DataOutputStream(new FileOutputStream(tmpFile)); T'9M
output.writeInt(nStartPos.length); !1@oZ(
for(int i=0;i<nStartPos.length;i++) c(Fo-4K
{ lE!.$L*k
// output.writeLong(nPos); :9(w~bB9$
output.writeLong(fileSplitterFetch.nStartPos); _@VKWU$$
output.writeLong(fileSplitterFetch.nEndPos); &B++ "f
} db}lN
output.close(); &vIj(e9Y
} >5zD0!bA
catch(IOException e){e.printStackTrace ();} ABL5T-*]
catch(Exception e){e.printStackTrace ();} 7M_GGjP
} F!2VTPm9z
YG)7+94
,u!_mV
//读取保存的下载信息（文件指针位置） \`%#SmQF
private void read_nPos() 4VkJtu5
{ lE*.9T
try{ Ih;D-^RQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KXUJ*l-5
int nCount = input.readInt(); R;uP^
nStartPos = new long[nCount]; 6Q&i=!fQ
nEndPos = new long[nCount]; " LhXR
for(int i=0;i<nStartPos.length;i++) |/Y!R>El
{ 238z'I+$G/
nStartPos = input.readLong(); VTi;y{
nEndPos = input.readLong(); @&9<)1F
} 84s:cO
input.close(); 2P{! n#"
} \lyHQ-gWhc
catch(IOException e){e.printStackTrace ();} = N:5#A
catch(Exception e){e.printStackTrace ();} .TNJuuO
} 6)FM83zk)K
pBn;:
P(3$XMx
private void processErrorCode(int nErrorCode) n@S|^cH
{ ^,[gO#hgz
System.err.println("Error Code : " + nErrorCode); %WYveY
} A-eCc#I
=,&{ &m)
e'=#G$S?g
//停止文件下载 db3.X~Cn#s
public void siteStop() 5"+;}E|q
{ dbF9%I@
bStop = true; 5j _[z|W2
for(int i=0;i<nStartPos.length;i++) J`wx72/-ZW
fileSplitterFetch.splitterStop(); U;gy4rj
k_Lv\'Ok
HDz"i
} 9'KOc5@l^
} =S\pI
//负责部分文件的抓取 lg 1r]
**FileSplitterFetch.java 8P&z@E{y
*/ Qr?(2t#
package NetFox; 0.1?hb|p5T
6*I=% H|
t3!~=U
import java.io.*; nzU0=w}V
import java.net.*; 59?$9}ob
HLh]*tQG
lvUWs
public class FileSplitterFetch extends Thread { ESe$6)P
RVpo,;:
C4|79UG>s
String sURL; //File URL j"&Oa&SH
long nStartPos; //File Snippet Start Position ,ZnL38GW
long nEndPos; //File Snippet End Position lnV!Xuf
int nThreadID; //Thread's ID cQ0+kX<
boolean bDownOver = false; //Downing is over Tcq@Q$H
boolean bStop = false; //Stop identical PW9tZx#
FileAccessI fileAccessI = null; //File Access interface lW]&a"1$
ZZ>(o d!B
u#3Cst8Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vQ{mEaH
{ )xTu|V
this.sURL = sURL; R5<:3tk=X
this.nStartPos = nStart; |lVi* 4za%
this.nEndPos = nEnd; vnX~OVz2
nThreadID = id; 8=mx5Gwz-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nm3CeU
} jW}hLjlN
CR-2>,*a9
F5\{`
public void run() XZ/cREz^s
{ ^5-SL?E
while(nStartPos < nEndPos && !bStop) /)r[}C0
{ Pa ^_s
Gk|T1%
#jw%0H;l]
try{ quFNPdP
URL url = new URL(sURL); q]y{ 4"=5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :/;;|lGw
httpConnection.setRequestProperty("User-Agent","NetFox"); eW[](lGWM
String sProperty = "bytes="+nStartPos+"-"; )U{IQE;T#
httpConnection.setRequestProperty("RANGE",sProperty); \Zn~y--Z
Utility.log(sProperty); Ystd[
hTQ]xN)
")W5`9
InputStream input = httpConnection.getInputStream(); y"ms;w'z
//logResponseHead(httpConnection); u/5)Yx+5_
DF"*[]^[
pAcu{5#7
byte[] b = new byte[1024]; ~B`H5#
int nRead; 1*B'o<?P1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .L_ Hk
{ =AeOkie
nStartPos += fileAccessI.write(b,0,nRead); No]#RvEd3
//if(nThreadID == 1) fc%C!^7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dewN\
} -nB. .q
gq+#=!(2
<{.pYrn
Utility.log("Thread " + nThreadID + " is over!"); H`T}k+e2-N
bDownOver = true; |PLWF[+t8
//nPos = fileAccessI.write (b,0,nRead); "T6s;'k
} p%e/>N.P
catch(Exception e){e.printStackTrace ();} a,[NcdG
} A)kdY!}
} g=S|lVQm
prVqV-S6TY
;oRgg'k<
//打印回应的头信息 w#;y
public void logResponseHead(HttpURLConnection con) SdJkno
{ t},71Ry
for(int i=1;;i++) <J^94-[CF
{ DXfQy6k'
String header=con.getHeaderFieldKey(i); wPpern05
if(header!=null) 3:gF4(.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0y/P
Utility.log(header+" : "+con.getHeaderField(header)); QH6_nZY
else ,uS}wJAX
break; !]#;'
} E1|:t$>Ld
} r5uX?^mJ0
.Kk'N
.vpx@_;]9
public void splitterStop() LLwC*)#
{ 3n1 >+8
bStop = true; }/F9(m
} ]#J-itO
|f+fG=a67V
=M34 HPG
} Qh4Z{c@
^+9i~PjL
8' +I8J0l
/* C0'_bTfB
**FileAccess.java D;X/7 p|>
*//文件访问(定位，写) \xOv9(
package NetFox; l`*R !\
import java.io.*; 'k9 1;T[
2;YL+v2
/3d6Og
public class FileAccessI implements Serializable{ h=ko_/<
r1|;V~a$~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bcFZ~B
RandomAccessFile oSavedFile; THnZbh4#)
long nPos; P64<O5l/
mvGj !'
7gT^ZL
public FileAccessI() throws IOException &fgfCZz'
{ Tw9?U,]
this("",0); -&r A<j
} XE :JL_
+L#Q3}=s
Bfr$&?j#
public FileAccessI(String sName,long nPos) throws IOException !o8(9F
{ |&rxDf}W
oSavedFile = new RandomAccessFile(sName,"rw"); Np R&`]
this.nPos = nPos; ykG^(.E
oSavedFile.seek(nPos); YRJw,xl
} b`DPf@p^kc
~.8p8\H
bF? {
public synchronized int write(byte[] b,int nStart,int nLen) O.OSLezTQ
{ &e1(|qax
int n = -1; R}\n@X*
try{ z4*`K4W
oSavedFile.write(b,nStart,nLen); k54Vh=p
n = nLen; 1WLaJ%Fv
} :%"$8o*0W
catch(IOException e) psE&Rx3)
{ !"N-To-c
e.printStackTrace (); UWq[K&vQZ
} T&kr IZw
R]Pv=fn
M`.v/UQn
return n; {~eVZVv
} %n>*jFC
L2^M#G@t
i 9wk)
} mEDi'!YE"
l*<RKY8
I?%iJ%
/* +`Ypc
**SiteInfoBean.java ?DKwKt
*/ ?ZT+4U00U
package NetFox; ($Ck5`_MK
y4~;H{!
S%k](\7!
public class SiteInfoBean { j43-YdCJ
@j?)uJ0Q
,.&y-?
private String sSiteURL; //Site's URL jsnk*>j
private String sFilePath; //Saved File's Path fkK42*U@r
private String sFileName; //Saved File's Name \Dr?}D
private int nSplitter; //Count of Splited Downloading File ".T&nS[z
(uskVK>L
@If ^5s;z
public SiteInfoBean() 8^6dK
{//nSplitter的缺省值为5 ^K n{L
//default value of nSplitter is 5 xdd;!HK,
this("","","",5); XKepk? E
} Dg2=;)"L
khtYn.eaL
\t\ZyPxn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) uGH>|V9'c
{ %,[p[`NRYR
sSiteURL= sURL; H8'_.2vwX
sFilePath = sPath; QAmb_:^"d
sFileName = sName; k874tD
this.nSplitter = nSpiltter; %vFoTu)2
mu}T,+9\
t^-yK;`?q:
} \w\{x0u
a}MSA/K(
^+zhzfJ
public String getSSiteURL() +Q6}kbDI
{ XhEd9>#
return sSiteURL; ;;g'C*_
} j^'op|l
/K<.$B8
?oO<PR}y
public void setSSiteURL(String value) n; fUwon
{ 9>na3ISh
sSiteURL = value; +Pm yFJH
} (r+#}z}
?Wz rv&E2
|VRzIA4M\
public String getSFilePath() O4i5fVy{
{ }+Ne)B E
return sFilePath; jLu`DKB
} K}p!W"!o
W4~:3Sk
Ot#O];3
public void setSFilePath(String value) iI(7{$y
{ 1"5-doo
sFilePath = value; dy%#E2f
} ypK1 sw
NWq>Z!x`
l3C%`[MB
public String getSFileName() s9'lw'
{ Mk~]0d
return sFileName; "]M]pR/j
} PA(XdT{
Vx6/Rehj
B5Y 3GWhrx
public void setSFileName(String value) 8V$:th('
{ ,AO]4Ec
sFileName = value; (d2|r)O
} RiX~YLeM
u79,+H@ep
ZH<:YOQ
public int getNSplitter() )|?s!rw +
{ *6trK`tx^
return nSplitter; /X_g[*]?
} q`8M9-~
H=j&uv8
DL0i
public void setNSplitter(int nCount) J<4egk4
{ oSOO5dk:z
nSplitter = nCount; xF4>D!T%8
} ,>rr|O
} Rr|&~%#z
{:;599l
*$I5_A8,.
/* D+ )R_
**Utility.java =E?!!EIq.
*/ |E YJbL;1%
package NetFox; C\B&'+uR
LK1 r@
VdZmrq;?/
public class Utility { 1k *gbXb
Uz`K#Bz
NBUSr}8|
public Utility() _*I@ J/
{ Uczb"k5
_*SA_.0
y.l`NTT]<
} "#a_--"k9
:bhpYEUMx
//线程睡眠 ^K#PcPF-j
public static void sleep(int nSecond) 9{;cp?\)M
{ +v`?j+6z
try{ lo%:$2*'p
Thread.sleep(nSecond); nK"XyZ&
} u&!QP4$"z
catch(Exception e) 2$MIA?A"Y
{ f;u<r?>Z
e.printStackTrace (); pS3TD"p
} MifPZQ
} \[Dxg`;4
IU8/B+hM~
//日志 x!A.**
public static void log(String sMsg) >Bj+!)96q
{ _djr>C=H"
System.err.println(sMsg); vyt$
} 1,tM
f"=1_*eH
s:6pPJL
public static void log(int sMsg) py9HUyr5eZ
{ 'ow`ej
System.err.println(sMsg); S|{'.XG
} *[-% .=[7
} >>ncq$
lAxbF
0 s-IW
/* nnV(MB4z1
**TestMethod.java VZ`L-P$AF
*/ ~qG`~/7
package NetFox; uK:?6>H
=lzRx%tm
hpxqL%r
public class TestMethod { aP%2CP~_P
rHir> p
| Vtd!9
public TestMethod() m@r+M"!R
{ ///xx/weblogic60b2_win.exe ]pZxbs&Vb
try{ \M H\!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RGw=!0V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [/s^(2%
SiteFileFetch fileFetch = new SiteFileFetch(bean); vgc#IEx@
fileFetch.start(); kIb)I(n
} 8Rgvb3u
catch(Exception e){e.printStackTrace ();} (o!v,=# 6{
Hqel1J
;^q@w
} j{i3lGaN
7gLN7_2
: "|M
public static void main(String[] args) V'XmMn)!
{ T+OQa+E@P
new TestMethod(); \,-t]$9
} e;y\v/A
} yEnurq%J
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