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)); -7l)mk
} W_N!f=HW
for(int i=0;i<nEndPos.length-1;i++) J#& C&S 2
{ CpF&Vy K
nEndPos = nStartPos[i+1]; E#cZM>
} vErlh:~e
nEndPos[nEndPos.length-1] = nFileLength; rN^P//
} !NFP=m1
} qy|si4IU8,
0FD+iID
LK[%}2me
//启动子线程 /_*L8b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u0& dDZ
for(int i=0;i<nStartPos.length;i++) DR6 OR B7
{ KUqD<Jj?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #r_&Q`!eU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *b0f)y3RV
nStartPos,nEndPos,i); \;smH;m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v(tr:[V
fileSplitterFetch.start(); 0Bpix|mq
} $VCWc#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hd}"%9p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [8QE}TFic
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lE?F Wt
nEndPos = " + nFileLength); _:tisr{
// fileSplitterFetch[nPos.length-1].start(); aGz<Yip
\WeGO.i-
`o~9a N
//等待子线程结束 D 4\T`j:
//int count = 0; }TCOm_Y/qL
//是否结束while循环 Vi~F Q
boolean breakWhile = false; c|'hs
]+B#SIC;
Sgt@G=_o
while(!bStop) [=Yfdh M8S
{ f`jRLo*L
write_nPos(); >aZ$x/U+Iw
Utility.sleep(500); YrR}55V,
breakWhile = true; MyOdWD&7
:h&*<!O2B`
IYy2EK[s
for(int i=0;i<nStartPos.length;i++) o|nj2.
{ WBA0! g98
if(!fileSplitterFetch.bDownOver) ? 1g<] ?
{ %@{);5[
breakWhile = false; m*BtD-{
break; PQ2u R
} 5UwaBPj4
} m3k}Q3&6Z
if(breakWhile) yp=2nU"o
break; TWC^M{e
.s_wP
m(Cn'@i`"0
//count++; zX!zG<<K
//if(count>4) W)F2X0D>
// siteStop(); (s,*soAN
} L44-: 3
*fq=["O
_AQ :<0/#
System.err.println("文件下载结束！"); ~h;c3#wuc
} qPpC)6-Q
catch(Exception e){e.printStackTrace ();} eA>O<Z1>
} AO9F.A<T5
/0 ,#c2aq
4b8!LzKS
//获得文件长度 )jp#|#h
public long getFileSize() Ftm%@S?
{ G1Cn[F;e
int nFileLength = -1; p3*}!ez4
try{ "6n~,$
URL url = new URL(siteInfoBean.getSSiteURL()); DY6wp@A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S*:b\{[f>
httpConnection.setRequestProperty("User-Agent","NetFox"); N`/6 By
2Ni$ (`"
~?dPF;.6_
int responseCode=httpConnection.getResponseCode(); )L`0VTw'M
if(responseCode>=400) a Kb2:1EQ
{ &gkloP@
processErrorCode(responseCode); S@zsPzw
return -2; //-2 represent access is error RaAi9b[/S
} gQ*0Mk
UGEC_
g!<@6\RB
String sHeader; Xi5ZQo!t
>(u=/pp=:
bzmT.!
for(int i=1;;i++) <?,o {
{ ~xu<xy@E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pSASMc@
//Utility.log(in.readLine()); cp2e,%o
sHeader=httpConnection.getHeaderFieldKey(i); @q2Yka
if(sHeader!=null) `w]=xe
{ VVvV]rU~
if(sHeader.equals("Content-Length")) ]xA;*b;|h
{ 4_`+&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DPi%[CRH
break; DVRE;+Jt
} 1A">tgA1
} N>7INK
else '>Y"s|
break; ]~)FMWQz-
} ld4QhZia
} 6Ez}A|i
catch(IOException e){e.printStackTrace ();} N/Z3 EF_
catch(Exception e){e.printStackTrace ();} {Os$Uui37\
9~<HTH
O(h4;'/E
Utility.log(nFileLength); kh 17
rFSLTbTf
!SD?
return nFileLength; LqPn$rZ|$
} B+wSLi(
bJ]g2C7`36
I' ej?~
//保存下载信息（文件指针位置） 7Xm pq&g
private void write_nPos() SPeSe/
{ 0CQ\e1S,#
try{ [(5;jUmF@
output = new DataOutputStream(new FileOutputStream(tmpFile)); V(A6>0s$|
output.writeInt(nStartPos.length); //\ORJd
for(int i=0;i<nStartPos.length;i++) Jt.dR6,
{ fnG&29x
// output.writeLong(nPos); ,+KZn}>
output.writeLong(fileSplitterFetch.nStartPos); 9@#Z6[=R,
output.writeLong(fileSplitterFetch.nEndPos); "CB*
} ngcXS2S_
output.close(); h2zuPgz,
} YL=?Nk/
catch(IOException e){e.printStackTrace ();} l];,)ddD9
catch(Exception e){e.printStackTrace ();} OOGqtA;
} kz(%8qi8&
Ajr]&H4
MZB0vdx
//读取保存的下载信息（文件指针位置） +g<2t,
private void read_nPos() Y{B|*[xM
{ 9Y- Sqk+
try{ .ZFs+8qU>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); * 'WzIk2
int nCount = input.readInt(); 3205gI,
nStartPos = new long[nCount]; ;+g p#&i`
nEndPos = new long[nCount]; 7KnZ
for(int i=0;i<nStartPos.length;i++) KY<>S/
{ ec[S?-
nStartPos = input.readLong(); :seo0w]
nEndPos = input.readLong(); z[B*sbS
} &7!&]kA+
input.close(); RRqHo~*0
} 0PIC|
catch(IOException e){e.printStackTrace ();} nKp='>Th
catch(Exception e){e.printStackTrace ();} R)"Ds}1G
} ce\]o^4
OWxYV$
{O*WLZ{0
private void processErrorCode(int nErrorCode) CDQ}C=4
{ 9Ruj_U
System.err.println("Error Code : " + nErrorCode); <->Nex
} ,OsFv}v7
lOt3^`
7c1xB.g
//停止文件下载 !s06uh
public void siteStop() fHCLsI
{ dq28Y$9~
bStop = true; XMd-r8yYr
for(int i=0;i<nStartPos.length;i++) s"#JBw\7
fileSplitterFetch.splitterStop(); NDEltG(
.8S6;xnkC
w7cciD|
} _nOJ.G
} Sg(fZ' -
//负责部分文件的抓取 L!Iu\_{q
**FileSplitterFetch.java 9}Ud'#E
*/ laG@SV
package NetFox; NK2Kw{c"iI
v*SSc5gFG
3zo]*6p0
import java.io.*; 9bRlSb@
import java.net.*; k3h,c;
Mo\LFxx>4{
_]a8lr+_-
public class FileSplitterFetch extends Thread { CpNnywDRwU
/L\]t
+dw$IMwb
String sURL; //File URL fCdd,,,}
long nStartPos; //File Snippet Start Position \Y&*sfQ
long nEndPos; //File Snippet End Position &^3KF0\Q
int nThreadID; //Thread's ID l2QO\O I9m
boolean bDownOver = false; //Downing is over Dj}n!M`2I
boolean bStop = false; //Stop identical i_Dv+^&zV
FileAccessI fileAccessI = null; //File Access interface D's'LspQ
}CnqJ@>C5
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 99w;Q 2k
{ <NZ^*]
this.sURL = sURL; xdb9oH
this.nStartPos = nStart; 7\m.xWX e
this.nEndPos = nEnd; <7N8L
nThreadID = id; ,S5tkTa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1ThONrxu
} .|[ZEXq
fmyyQ|]O"
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public void run() >=Hm2daN
{ lPF(&pP
while(nStartPos < nEndPos && !bStop) vH/z|<
{ P=PcO>
UmYReF<<_
t)P5bQ+$u9
try{ -6a4H?L
URL url = new URL(sURL); k~f3~-"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GWo^hIfJ
httpConnection.setRequestProperty("User-Agent","NetFox"); os6p1"_\f
String sProperty = "bytes="+nStartPos+"-"; S-V)!6\cK
httpConnection.setRequestProperty("RANGE",sProperty); [SGt ~bRJ
Utility.log(sProperty); c&r8q]u
Gh}k9-L
mi9BC9W(
InputStream input = httpConnection.getInputStream(); M,xhQ{eBY
//logResponseHead(httpConnection); KNT(lA0s
q] g'rO'
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byte[] b = new byte[1024]; (qd$wv^h
int nRead; 4a3Xz,[(a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \l!^6G|c
{ /N6sH!w
nStartPos += fileAccessI.write(b,0,nRead); pW ]+a0j
//if(nThreadID == 1) tYV%izE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `L p3snS
} Z* eb
Sh'>5z2
Hik8u!#P
Utility.log("Thread " + nThreadID + " is over!"); _~!*|<A_
bDownOver = true; 6&/H XqP
//nPos = fileAccessI.write (b,0,nRead); 8tq6.%\
} ?^]29p_
catch(Exception e){e.printStackTrace ();} 46(Vq|
} Ar&]/X,WG
} wn*<.s
XrR@cDNx{
DVCO( fz
//打印回应的头信息 }#~@HM>6Z
public void logResponseHead(HttpURLConnection con) Y4*ezt:;Q
{ v&g(6~b_>
for(int i=1;;i++) n{vp&
{ |lH~nU.*
String header=con.getHeaderFieldKey(i); q~*3Bk~
if(header!=null) s+Qm/ h2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .5=Qfvi*
Utility.log(header+" : "+con.getHeaderField(header)); RqTW$94RD
else mq~rD)T
break; W[S4s/)mg
} AWlR" p2
} nLK%5C
U9:?d>7
:x e/7-
public void splitterStop() gb 6 gIFq;
{ 2w`kh=
bStop = true; BNU]NcA#*,
} C6Qnn@waYb
d;(&_;
n99>oh
} :UjHP}s
aYQ!`mS::M
q^}QwJw
/* cVv>"oF;~*
**FileAccess.java )W^Wqa8mG|
*//文件访问(定位，写) p"^^9'`=
package NetFox; uS :3Yo
import java.io.*; ) *:<3g!
2!QS&i
l'YpSO~l7
public class FileAccessI implements Serializable{ c_b^t09
x#yL&+'?Mj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <qH>[\
RandomAccessFile oSavedFile; f:L%th
long nPos; n y6-_mA]
(bH*i\W
7NG^X"N{Ul
public FileAccessI() throws IOException ` c~:3^?9d
{ (mXV5IM
this("",0); e"en ma\_
} 4)Y=)#=
`T $lTP
nIVPh99
public FileAccessI(String sName,long nPos) throws IOException PQAN,d
{ NC::;e
oSavedFile = new RandomAccessFile(sName,"rw"); D6Ov]E:fa
this.nPos = nPos; Q1V4bmM
oSavedFile.seek(nPos); qA:CV(Z
} #tG/{R
m;o \.s
N3E Qq~lX
public synchronized int write(byte[] b,int nStart,int nLen) +GMM&6<
{ :pQZ)bF
int n = -1; (PU0\bGA
try{ ry}CND(nB
oSavedFile.write(b,nStart,nLen); 2vWJ|&|p
n = nLen; {>>ozB.
} /Kb7#uq
catch(IOException e) 8^ju=
{ B&|F9Z6D
e.printStackTrace (); l<)(iU
} bnLvJ]i)
P7d" E
m *8[I
return n; l){l*~5zl2
} Q(gu";&
s&Y~48{
-?<wvUbR{
} R{)Sv|+`
D8slSX`6j
7}(LO^,A
/* nab:y(]$/
**SiteInfoBean.java %b'ic
*/ hu[=9#''$
package NetFox; <QTu"i
[qlq&?"
]OZZPo
public class SiteInfoBean { HH+NNSRO
#B:J7&@fn
iyrUY
private String sSiteURL; //Site's URL V| z|H$-
private String sFilePath; //Saved File's Path y!GjC]/
private String sFileName; //Saved File's Name *ghkw9/
private int nSplitter; //Count of Splited Downloading File K,%H*1YKK
i}ypEp
Fgxh?Wd9
public SiteInfoBean() HY9H?T
{//nSplitter的缺省值为5 +pc_KR
//default value of nSplitter is 5 N:[m,U9a
this("","","",5); VkhZt7]K}B
} g"( vl-Uw
,XCC#F(d1
4JFi|oK0H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PTIC2
{ }qT @.
sSiteURL= sURL; ui`xgR\6Rh
sFilePath = sPath; z,}1K!
sFileName = sName; O\pqZ`E=s
this.nSplitter = nSpiltter; r vVU5zA4H
>>Hsx2M
-w=rNlj
} Pk[f_%0
"2+>!G RQ
FyJI@PZdI-
public String getSSiteURL() v<_}Br2I[
{ wwnc
return sSiteURL; 2{!'L'km
} 3X*;.'#Z
's@v'u3
IK(G%dDw
public void setSSiteURL(String value) ,ZV<o!\
{ gWqmK/.U.0
sSiteURL = value; 7xB#)o53
} VXZdRsV8T
*pw:oTO
+`u]LOAyP=
public String getSFilePath() 6g29!F`y
{ ;5ugnVXu
return sFilePath; 0aSN8
} WW0N"m'
c%>t(ce`Tl
s2_j@k?%
public void setSFilePath(String value) Lg|j0-"N
{ l Vo](#W
sFilePath = value; HGfYL')Z
} Dd<gYPC
B{H;3{0
Q/\ <rG4
public String getSFileName() qc|;qPj
{ [ hm/B`t*e
return sFileName; 2$yKa5SaX
} WTA0S}pT
>*,Zc
T5B~CC'6
public void setSFileName(String value) KArf:d
{ RR{]^g51
sFileName = value; <d#9d.<
} ymY,*Rb
jkQv cU
vlw2dY@^
public int getNSplitter() tNjb{(eO\h
{ U&C\5N]
return nSplitter; uZz^>*b
} '1~mnmiP
)_NQ*m
Ik>sd@X*|
public void setNSplitter(int nCount) !\JG]2 \
{ #E5Sc\,
nSplitter = nCount; fxI>FhU_
} h#^IT
} yf*MG&}
{[hV['Awv
%g5weiFM
/* kMo;<Z
**Utility.java .r[DqC
*/ ?q7VB
package NetFox; r9%4q4D?>9
MkC25
7Nh6 `
public class Utility { 0 !E* >
28d:
r|fJ~0z
public Utility() R5X<8(4p
{ !a[ voUS
IJD'0/R'c
Fb*^GH)J
} |D$U{5}Mv
@+syD
//线程睡眠 ]8htJ]<|Q
public static void sleep(int nSecond) YMIDV-
{ uWG'AmK_#E
try{ 7{D+\i
Thread.sleep(nSecond); Iu2RK
} -qs.'o ;2
catch(Exception e) qe"5&cc1
{ wDem }uO
e.printStackTrace (); 5G_*T
} Xleoh2&M
} +@cf@}W6QC
4^w>An6
//日志 r1}OlVbK
public static void log(String sMsg) CmJI"
{ {p9y{$
System.err.println(sMsg); A>%fE 6FY
} jXGr{n
)cUc}Avg}
7eQ7\,^H
public static void log(int sMsg) jzI\Q{[m'
{ HMgZ&v
System.err.println(sMsg); 00%$?Fyk
} lk}R#n$
} "%A/bv\u
wI #_r_
o8KlY?hX
/* w<J$12 "p+
**TestMethod.java $*b>c:
*/ }f^K}*sK$5
package NetFox; t<|=-
r7C m
NX@TWBn%
public class TestMethod { UB.FX
@-kzSm
{Ylj]
public TestMethod() =XQ3sk6U
{ ///xx/weblogic60b2_win.exe %a8'6^k
try{ ^^jF*)DT@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s]5wzbFO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Fc*^8$ryC
SiteFileFetch fileFetch = new SiteFileFetch(bean); qk~QcVg
fileFetch.start(); Gd%6lab
} nl*{@R.q @
catch(Exception e){e.printStackTrace ();} ;?=nr5;q
5>KAVtYvc
E0ud<'3<
} :n0(gB
QMy;?,
[5)1 4% x
public static void main(String[] args) y"cK@sOo
{ SN?jxQ
new TestMethod(); #8;^ys1f
} z ]o&^Q
} y<BiR@%,7
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