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)); q]Gym 7o
} R~u0!
for(int i=0;i<nEndPos.length-1;i++) DArEIt6Q
{ [OJ@{{U%
nEndPos = nStartPos[i+1]; K%9PIqK?4
} AnVj '3
nEndPos[nEndPos.length-1] = nFileLength; v w$VRPW
} .&d]7@!qy
} @=ABO"CQ
r2?-QvQ
F,{M!dL
//启动子线程 zA[6rYXY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PZ2$ [s0W
for(int i=0;i<nStartPos.length;i++) et]-;(M
{ \F=w~ $)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^luAX }*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (9q61zA
nStartPos,nEndPos,i); "orZje9AC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cQEK>aAd
fileSplitterFetch.start(); AP.WTFf
} %0 (,f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hPtSY'_@_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w :2@@)pr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sd?:+\bS;
nEndPos = " + nFileLength); :@KU_U)\
// fileSplitterFetch[nPos.length-1].start(); {`fhcEC
1GB$;0 W),
krwY_$q
//等待子线程结束 ]F5?>du@~
//int count = 0; ##VS%&{
//是否结束while循环 g+8{{o=
boolean breakWhile = false; +P,hT
#I[tsly}
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while(!bStop) lVY`^pw?
{ !fF1tW
write_nPos(); D-*`b&i48
Utility.sleep(500); S8;Dk@rr(y
breakWhile = true; g+BW~e)
RE/'E?G
*IWO ,!
for(int i=0;i<nStartPos.length;i++) z VleJ!d
{ tU7,nE>p
if(!fileSplitterFetch.bDownOver) A2 r1%}{
{ )@)wcf!b
breakWhile = false; |GgFdn`>
break; ?_36uJo}
} "e62g
} +@D [%l|
if(breakWhile) SPKGbp&
break; ,lSt}Lml
?2hoY
J$6tCFD
//count++; _YzItge*
//if(count>4) Q" BIk =
// siteStop(); 8 PI>Q
} kQ4-W9u
%g7 !4
9`4mvK/@
System.err.println("文件下载结束！"); k&|L"N|w
} qk~ni8
catch(Exception e){e.printStackTrace ();} JmB7tRM8
} Lf_`8Ux
`` (D01<
0/?V _
//获得文件长度 o>x*_4[
public long getFileSize() @czNiWU"4;
{ .Ymoh>JRL
int nFileLength = -1; +')\,m "z
try{ Sz4YPl
URL url = new URL(siteInfoBean.getSSiteURL()); )70-q yA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I]N?}]uZ
httpConnection.setRequestProperty("User-Agent","NetFox"); $ ;cZq
xVHZZ?e
VS0 &[bl
int responseCode=httpConnection.getResponseCode(); l6ayV
if(responseCode>=400) NT?Gl(
{ PR?Ls{}p\
processErrorCode(responseCode); %rVC3}
return -2; //-2 represent access is error Up?w>ly
} d5&avL\
b%<-(o/
bL\ab
String sHeader; +O P8U]~
"PH}\Dl=
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for(int i=1;;i++) E O^j,x g
{ /Zw^EM6c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j4H]HGHv
//Utility.log(in.readLine()); ]kUF>Wp
sHeader=httpConnection.getHeaderFieldKey(i); Yt79W
if(sHeader!=null) F9(*MP|
{ /bm$G"%d
if(sHeader.equals("Content-Length")) !4zSE,1
{ Dz$GPA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V+My]9ki
break; urmx})=
} M.|O+K z
} 71`)@y,Z,
else mX))*e4k
break; {xb8H
} dLl/V3C6t
} lA}(63j+b
catch(IOException e){e.printStackTrace ();} e]-bB#-A
catch(Exception e){e.printStackTrace ();} LAqmM3{fA
@Bs7kjuX
F|\^O[#R
Utility.log(nFileLength); x*GGO)r
yT<6b)&*&
TZ8:3ti
return nFileLength; ^hPREbD+f
} "&(.Z(
S*,DX~vig
ST'M<G%4E
//保存下载信息（文件指针位置） `j+aAxJ=\
private void write_nPos() Wt=QCutt
{ WK;X6`
try{ ?v8.3EE1\o
output = new DataOutputStream(new FileOutputStream(tmpFile)); $g? ]9}p
output.writeInt(nStartPos.length); :D(4HXHK%
for(int i=0;i<nStartPos.length;i++) W@<(WI3
{ e<wA["^
// output.writeLong(nPos); C-Y~T;53
output.writeLong(fileSplitterFetch.nStartPos); 4%#Y)zo.e
output.writeLong(fileSplitterFetch.nEndPos); V<&x+?>S
} x {Z_rD
output.close(); J`/t;xk
} >*/\Pg6^
catch(IOException e){e.printStackTrace ();} Q;A1&UA2
catch(Exception e){e.printStackTrace ();} =+24jHs
} +>BLox6
v eP)ElX
UYJMW S=
//读取保存的下载信息（文件指针位置） u0^Vy#@_
private void read_nPos() TC7&IqT
{ c^$_epc*
try{ B->3/dp2c'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )BI6nU
int nCount = input.readInt(); QN`K|,}H^
nStartPos = new long[nCount]; m~`d<RM/
nEndPos = new long[nCount]; rqJ'm?>cr
for(int i=0;i<nStartPos.length;i++) N]gJ(g
{ >2Z0XEe
nStartPos = input.readLong(); G Y??q8
nEndPos = input.readLong(); pW{Q%"W
} O |45r
input.close(); ?U+^ctwv7
} {C+blzh6
catch(IOException e){e.printStackTrace ();} Wtl/xA_
catch(Exception e){e.printStackTrace ();} Zj,1)ii
} 37C'knW
r@e/<bz9
(C{l4
private void processErrorCode(int nErrorCode) .!#0eAT
{ nymF`0HYe1
System.err.println("Error Code : " + nErrorCode); $7k"?M_
} -!_f-Nny
qfJi[8".
OP:i;%@c
//停止文件下载 \VQv "wid
public void siteStop() C(N' +VV_
{ / =]h@m-`
bStop = true; 3$<u3Zi6
for(int i=0;i<nStartPos.length;i++) UZJ^e$N
fileSplitterFetch.splitterStop(); L'1!vu *Rg
SZVNu*G!H
yjcZTvjJ
} wm1`<r^M.
} *`D}voU
//负责部分文件的抓取 pxf(C<y6_
**FileSplitterFetch.java Bi}uL)~rD
*/ M8_f{|!&
package NetFox; ;U+4!N
QT\||0V~p
Ag[Zs%X
import java.io.*; Kkfza
import java.net.*; 2HA-q),6
{owXyQ2mK
dJYsn+
public class FileSplitterFetch extends Thread { "AN*2)e4
h2k"iO}
6}z-X*
String sURL; //File URL ZLP)i;Az
long nStartPos; //File Snippet Start Position +pcGxje\
long nEndPos; //File Snippet End Position ^"lVTDsU
int nThreadID; //Thread's ID AvP$>Alc
boolean bDownOver = false; //Downing is over 3C[#_&_l
boolean bStop = false; //Stop identical f\p#3IwwH
FileAccessI fileAccessI = null; //File Access interface }%^N9AA8
:%&|5Ytb
)P13AfK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException TH[xSg
{ AW{"9f4
this.sURL = sURL; Gm`#0)VC
this.nStartPos = nStart; zWs("L(#s
this.nEndPos = nEnd; h7r*5E
nThreadID = id; }4Q~<2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3?%?J^/a
} asEk3
w.7pD
8Pb~`E/
public void run() -BV8,1
{ 3@}rO~
while(nStartPos < nEndPos && !bStop) zD"n7;
{ qdW"g$fW
*'i9
{[I]pm~n
try{ ey/{Z<D
URL url = new URL(sURL); <cof
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $O'IbA
httpConnection.setRequestProperty("User-Agent","NetFox"); QUQw/
String sProperty = "bytes="+nStartPos+"-"; Am'%tw ~
httpConnection.setRequestProperty("RANGE",sProperty); M6nQ17\{
Utility.log(sProperty); b((>?=hh
Jn:h;|9w
ax)>rP,V
InputStream input = httpConnection.getInputStream(); Q9G\T:^ury
//logResponseHead(httpConnection); =Ch^;Wyt
|Eyn0\OA
uM"_3je{W2
byte[] b = new byte[1024]; DXI{ jalL
int nRead; &~Hx!]uc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pie8 3Wy>
{ Y5fz_ [("
nStartPos += fileAccessI.write(b,0,nRead); SH1S_EQ<
//if(nThreadID == 1) @ajt D-_2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IGnP#@`5]
} 5eLm
SSQB1c
luWr.<1
Utility.log("Thread " + nThreadID + " is over!"); urbSprdF
bDownOver = true; W9D~:>^YP
//nPos = fileAccessI.write (b,0,nRead); <5 )F9.$
} $-i(xnU/nl
catch(Exception e){e.printStackTrace ();} /:Q
} mu*RXLai
} ''Y'ZsQ;
`R!%k]$
:L+%5Jq
//打印回应的头信息 9)?_[|2
public void logResponseHead(HttpURLConnection con) ~T^,5Tz1j
{ cM_!_8o
for(int i=1;;i++) x DiGN Jc
{ cjp~I/U
String header=con.getHeaderFieldKey(i); ,f@\Fs~n
if(header!=null) xNd p]u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w/f?KN
Utility.log(header+" : "+con.getHeaderField(header)); ,,c+R?D
else ?E}9TQ
break; -UoTBvObAm
} ]r\FC\n6e
} :Tcvj5
*'cyFu$
<kCOg8<y :
public void splitterStop() @P)2ZGG
{ Di"Tv<RlQ
bStop = true; egmNX't6f5
} yZV Y3<]
r"|UgCc
5AbY 59
} XiMd|D
Q?2GwN
Nu;?})tF
/* HcQ)XJPK
**FileAccess.java QJy1j~9x
*//文件访问(定位，写) 2,6~;R
package NetFox; 0N87G}Xu
import java.io.*; mUNAA[0 L
9RPZj>ezjA
%"Ia]0
public class FileAccessI implements Serializable{ (M2hK[
M?_7*o]!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7n)ob![\d
RandomAccessFile oSavedFile; /!'Png0!
long nPos; w `nm}4M
T'ei>]y]
TD sjNFe3
public FileAccessI() throws IOException [XhG7Ly
{ 60G(jO14
this("",0); Alk+MwjR
} `t"7[Zk
<{T5}"e
$ ~%w21?&
public FileAccessI(String sName,long nPos) throws IOException 2~l+2..
{ xOx=Z\ c
oSavedFile = new RandomAccessFile(sName,"rw"); /Un\P
this.nPos = nPos; - -\eYVh[
oSavedFile.seek(nPos); qjsEyro$-
} " ?Ux\)*
ti^=aB
H0f]Swh0a
public synchronized int write(byte[] b,int nStart,int nLen) tM|/OJ7
{ t)5.m}
int n = -1; BJt]k7ku+
try{ S6<#] 6Z
oSavedFile.write(b,nStart,nLen); =h70!) Z5
n = nLen; DYF(O-hJK
} QM'|k6
catch(IOException e) \fsNI T/
{ rvacCwI
e.printStackTrace (); P(UY}oU
} +G6 Ge;
0a2#36;_IK
3a[LM!
return n; dZY|6
} rJ{k1H>
Z,DSTP\|
8!{ }WLwb
} +Ks3
"rrw~
vm7ag 7@O
/* Rk-G|52g
**SiteInfoBean.java zE Ly1v\"
*/ A34O(fE
package NetFox; -,Js2+QZ#
~z(0XKq0d
nsM.`s@V
public class SiteInfoBean { %d%FI"!K
*'*,mfk[
?OPuv5!pI
private String sSiteURL; //Site's URL |l-O e
private String sFilePath; //Saved File's Path RBfzti6
private String sFileName; //Saved File's Name vJ{F)0 K
private int nSplitter; //Count of Splited Downloading File nIZsKbnw
QnJLTBv
kRr/x-"
public SiteInfoBean() eE_$ADEf
{//nSplitter的缺省值为5 O6,2M[a
//default value of nSplitter is 5 _kc}:
this("","","",5); &7,::$cu
} [Op^l%BC
KF1Zy;
iaJLIrl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E5#ff5
{ \<hHZS
sSiteURL= sURL; LLFQ5py{
sFilePath = sPath; * H~=dPC
sFileName = sName; [%P[ x]-
this.nSplitter = nSpiltter; f1S%p
HRyhq;C
p({Lp}'
} c_>AbF{
]a`"O
|S~$IFN4
public String getSSiteURL() gb4$W@N7V
{ M?=I{}!@Q
return sSiteURL; Fn0|v66
} 6b%IPbb
ArjRoXDE
(w#)|9Cxm
public void setSSiteURL(String value) 4 aE{}jp1
{ M(yWE0 3
sSiteURL = value; &^w"
} m?gGFxo
.<E7Ey#
1JJ1!& >
public String getSFilePath() $ce*W9`
{ Ly/
return sFilePath; 0176
} @FZ_[CYg
@LFB}B
t&p I
public void setSFilePath(String value) XwfR/4
{ AyW=.
sFilePath = value; |26[=_[q
} ;>/yY]F7
XZS%az1%
K2\)9
public String getSFileName() ^(Z%,j3O
{ 9KB}?~Nx4
return sFileName; M]M>z>1*v
} y\4/M6
7SN61)[m
acar-11_o/
public void setSFileName(String value) Sb?Ua*(L:
{ K'/if5>Bc
sFileName = value; +J~%z*A
} tSnsjd<6.
y(/5l
=c$x xEDD
public int getNSplitter() Q/]o'_[vW
{ sxS%1hp3
return nSplitter; a#G3dY>
} Pd& Npp3
R^=v&c{@
ay||yn:
public void setNSplitter(int nCount) hrO9_B|#
{ *>`6{0,9
nSplitter = nCount; {;th~[
} z,hBtq:-$
} ir>S\VT4
Vugb;5Vl
Vrd16s
/* sP}u zS
**Utility.java x%O6/rl
*/ s"J)Jc
package NetFox; ,t;US.s([.
'/OQ[f=K
)Z|G6H`c3
public class Utility { QN?EI: q=
j:>0XP
4.uaWM)2
public Utility() 3Agyp89}Q
{ %C@p4
y"ss<`Cn
3IjsV5a
} eE=2~ ylU
>4-9 @i0FV
//线程睡眠 #6~Bg)7AM
public static void sleep(int nSecond) a1Q%Gn@R
{ 4*9t:D|}
try{ QSn18V>{
Thread.sleep(nSecond); `S5::U6E
} ;<;~;od*/
catch(Exception e) '\+"3!$
{ Wv9L}@J
e.printStackTrace (); ^u#iz
} Rjlp<
} Yh;(puhyA
Lz p}<B
//日志 tZVs0eVF<
public static void log(String sMsg) ,c0LRO
{ C^5 V
System.err.println(sMsg); \x\N?$`ANc
} >T\@j\X4
IbJl/N%o
O:a=94
public static void log(int sMsg) >dJ~
{ $+ N~Fa
System.err.println(sMsg); `W" ;4A
} ij~-
} S0gxVd(
h^qZi@L
F u^j- Io
/* f[.'V1
**TestMethod.java rlawH}1b
*/ ~Hv>^u Mh
package NetFox; J .TK<!
$~/cxLcT
WHOX<YJs
public class TestMethod { Iz-mUD0;
Q<g>WNb
/Hq
public TestMethod() ~tV7yY|zr
{ ///xx/weblogic60b2_win.exe 7fO<=ei:
try{ I"x~ 7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A>e-eD xi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |5:2?S2R
SiteFileFetch fileFetch = new SiteFileFetch(bean); _dz ZS(7M6
fileFetch.start(); }p)Hw2
} >SLmlK
catch(Exception e){e.printStackTrace ();} p >ua{}!L
-*~ @?
vfvp#
} J7- vB",U
42A'`io[w]
Y'bz>@1(
public static void main(String[] args) MP<]-M'|<
{ W[qy4\.B
new TestMethod(); rFkZ'rp74b
} $pAVTz
} L6i|5 P
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