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)); ?5cI'
} <U >>ZSi
for(int i=0;i<nEndPos.length-1;i++) .0rh y2
{ U1RpLkibQ
nEndPos = nStartPos[i+1]; TGe;HZ
} oifv+oY
nEndPos[nEndPos.length-1] = nFileLength; l0cA6b
} C@W"yYt
} )ZqJh
+0q>fp_K(+
2e9es
//启动子线程 }S$@ Ez6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y2vUthRwo
for(int i=0;i<nStartPos.length;i++) WjwLM2<nK7
{ H& Ca`B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mPP`xL?T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FR!? #!
nStartPos,nEndPos,i); '07P&g-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !M]\I&
fileSplitterFetch.start(); aj,T)oDbt6
} ) ^3avRsC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _Bp1co85MQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); oK%K}{`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *9c!^$V
nEndPos = " + nFileLength); e=;AfK
// fileSplitterFetch[nPos.length-1].start(); 7=OQ8IM!
OP|8Sk6 r
X>. NFB
//等待子线程结束 YH_7=0EJ
//int count = 0; 70mpSD3
//是否结束while循环 z,:a8LB#[
boolean breakWhile = false; [.*;6y3
T%n2$
\$OF1i@
while(!bStop) pzgSg[|
{ ,b;{emX h
write_nPos(); o9S+6@
Utility.sleep(500); TkO[rAC
breakWhile = true; /?1nHBYPM
lmSo8/%T
N**g]T 0`
for(int i=0;i<nStartPos.length;i++) _fP&&}
{ dG71*)<)t
if(!fileSplitterFetch.bDownOver) .rJiyED?!
{ m&iH2|
breakWhile = false; f5==";eP
break; wL^%w9q-
} t/PlcV_M"
} ;kJA'|GX
if(breakWhile) V$rlA'+1v
break; 2kUxD8BcN
uH;-z_Wpn!
d'Axum@
//count++; vuFBET,
//if(count>4) UD y(v]
// siteStop(); BMIyskl=i
} EmT`YNuc
h}Wdh1.M3
{gaai
System.err.println("文件下载结束！"); ,mL !(US
} `[YngYw
catch(Exception e){e.printStackTrace ();} EK$Kee}~
} s{4\xAS>
oo$MWN8a>r
\rV B5|D?
//获得文件长度 &X]\)`j0
public long getFileSize() U70]!EaT
{ ow'lRHZ
int nFileLength = -1; 45H!;Qsk
try{ |uH%6&\
URL url = new URL(siteInfoBean.getSSiteURL()); "uPy,<l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xT)psM'CL
httpConnection.setRequestProperty("User-Agent","NetFox"); LN_OD5gZ
$8BE[u|H2
Sj(F3wY
int responseCode=httpConnection.getResponseCode(); Jj^GWZRu
if(responseCode>=400) X{-9FDW
{ kV Rn`n0
processErrorCode(responseCode); RP`2)/sMT
return -2; //-2 represent access is error a/uo}[Y
} Zzl,gy70
da$BUAqU
9(!]NNf!
String sHeader; >uI$^y1D
:Ld!mRZF
vG2b:[W
for(int i=1;;i++) @)8]e S7
{ YO:&;K%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bO/*2oau
//Utility.log(in.readLine()); gK3Mms]}m
sHeader=httpConnection.getHeaderFieldKey(i); K$REZe
if(sHeader!=null) /MOnNnV
{ [&P`ak
if(sHeader.equals("Content-Length")) uC]Z8&+obb
{ e^$j5jV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^`qPs/b
break; O:.,+,BH
} W%!@QY;E(
} c~dM`2J,
else \`,xgC9K
break; B">yKB:D}t
} u:`y]
} aN^IP
catch(IOException e){e.printStackTrace ();} Nl8 gK{
catch(Exception e){e.printStackTrace ();} twk&-:'
M}.b" ljZ
<kD#SV%"
Utility.log(nFileLength); -0,4egj3
I*1S/o_xI
CM~MoV[k7e
return nFileLength; -'C!"\%
} !g0cC.'
mT_GrIl[
iG[? ]]
//保存下载信息（文件指针位置） Ls:=A6AGM
private void write_nPos() "~p+0Xws9
{ nJVp.*S
try{ mPmB6q%)]
output = new DataOutputStream(new FileOutputStream(tmpFile)); -WT3)On
output.writeInt(nStartPos.length); Z%v6xP.
for(int i=0;i<nStartPos.length;i++) `X+j2TmS
{ 4S *,\q]q
// output.writeLong(nPos); 4=p@2g2"H
output.writeLong(fileSplitterFetch.nStartPos); c)1=U_61
output.writeLong(fileSplitterFetch.nEndPos); "oE*9J?e
} U4wpjHg
output.close(); x9}++r
} :z~!p~
catch(IOException e){e.printStackTrace ();} 9)Yw :
catch(Exception e){e.printStackTrace ();} sA_X<>vAKJ
} :k1$g+(lP
,z66bnjO
5L&:_iQZy
//读取保存的下载信息（文件指针位置） VBx,iuaw
private void read_nPos() [$2qna2VP
{ piu0^vEEH
try{ HtzMDGV<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9U10d&M(
int nCount = input.readInt(); $GF&x>]]
nStartPos = new long[nCount]; W#45a.v
nEndPos = new long[nCount]; h[l{ 5Z*
for(int i=0;i<nStartPos.length;i++) <R~KM=rL
{ ;Prg'R[o;
nStartPos = input.readLong(); 1b`G2?%
nEndPos = input.readLong(); ?-{IsF^
} .cw=*<zeg
input.close(); \G=bj;&eF
} N<bD
catch(IOException e){e.printStackTrace ();} `GkRmv*
catch(Exception e){e.printStackTrace ();} &enlAV'#)O
} kGj]i@(PA4
jf7pl8gv
Isp_U5M
private void processErrorCode(int nErrorCode) W^ClHQ"Iy
{ x9\J1\
System.err.println("Error Code : " + nErrorCode); sbjtL,
} 83xd@-czgh
(lb`#TTGx
>%i9oI<)
//停止文件下载 ,^!Zm^4,
public void siteStop() eu=|t&FKk
{ Zr R+QV
bStop = true; K*[0dza$
for(int i=0;i<nStartPos.length;i++) rUvwpP"k
fileSplitterFetch.splitterStop(); ;y,NC2Xj
H>Sf[8w)%
S r[IoF)
} EUXV/QV{
} gx#J%k,f
//负责部分文件的抓取 5#BF,-Jv
**FileSplitterFetch.java 9`,,%vdj
*/ _jk|}IB;X
package NetFox; F94V5_[
],$6&Cm
6e&g$R v
import java.io.*; }RH lYN
import java.net.*; #VQ36pCd
4=UI3 2v3
\4C)~T:*
public class FileSplitterFetch extends Thread { ^U" q|[qy
S{Rh'x\B
d[yrNB6|
String sURL; //File URL Age-AJ
long nStartPos; //File Snippet Start Position [gTQ-
long nEndPos; //File Snippet End Position ?#U0eb5u
int nThreadID; //Thread's ID M'b:B*>6
boolean bDownOver = false; //Downing is over yi&?d&rK
boolean bStop = false; //Stop identical kzW\z4f
FileAccessI fileAccessI = null; //File Access interface V5cb}xx
y}CkzD
jDFp31_X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Xk 5oybDI
{ fdg[{T4:
this.sURL = sURL; ,&-S?|
this.nStartPos = nStart; wYC9~ms-
this.nEndPos = nEnd; mMn2(
nThreadID = id; IQo]9Lx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Cl%V^xTb
} 1 VPg`+o
p, !1 3X
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public void run() iJ5e1R8tN
{ 4+BrTGp
while(nStartPos < nEndPos && !bStop) Y=PzN3
{ p!. /
:Fw *r|
]Fb8.q5(Y
try{ j*zB { s K
URL url = new URL(sURL); Iwnj'R7:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DX]z=d)tc
httpConnection.setRequestProperty("User-Agent","NetFox"); IEKMa
String sProperty = "bytes="+nStartPos+"-"; +#&el//
httpConnection.setRequestProperty("RANGE",sProperty); 2l]C55p)s
Utility.log(sProperty); H57jBD
{mKpD
$IZ*|>(
InputStream input = httpConnection.getInputStream(); :YkDn~@
//logResponseHead(httpConnection); WBIQ%XB'
^!zJf7(+<>
yQ72v'
byte[] b = new byte[1024]; C@l +\M(
int nRead; _N[^Hl`\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a,en8+r]
{ UMnR=~.
nStartPos += fileAccessI.write(b,0,nRead); .H*? '*
//if(nThreadID == 1) ua6*zop
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WV9[DFU
} o.v,n1Nm
BxW||O|_N"
EbHUGCMO
Utility.log("Thread " + nThreadID + " is over!"); @U7U?.p
bDownOver = true; LNsE7t
//nPos = fileAccessI.write (b,0,nRead); <"j"h=tm}
} ?dATMmT-
catch(Exception e){e.printStackTrace ();} D*<8e?F
} [U+<uZzOC
} Lx4H/[$6D
C5W-B8>
b*$o[wO9
//打印回应的头信息 z^SN#v$
public void logResponseHead(HttpURLConnection con) O~c+$(
{ j[Hg]
for(int i=1;;i++) G5X|JTzpu<
{ cqU$gKT
String header=con.getHeaderFieldKey(i); x&6i@Jl
if(header!=null) )aO!cQ{s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `zV-1)=
Utility.log(header+" : "+con.getHeaderField(header)); PhI{3B/
else =r@ie>*U
break; U iPVZ@?
} C$EFh4
} j+ T\c2d
\t7zMp
ZS 7)(j$.
public void splitterStop() @b(gjOE
{ '!2
bStop = true; !'UsC6Y4
} tL 9e~>,`
vzgudxG'z
v6, o/3Ex
} %.r5E2'
zv3<i (
1tK6lrhj
/* Zzzi\5&gU
**FileAccess.java 2*cKFv{
*//文件访问(定位，写) {Rh+]=7
package NetFox; 62KW HB9S
import java.io.*; E].a|4sh
OYCFx2{
r+WPQ`Ar
public class FileAccessI implements Serializable{ p>hCh5
:8/M6-EK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V3Rnr8
RandomAccessFile oSavedFile; Z6HkQ=A64
long nPos; h;h,dx
>0G}, S
5;uX"zG
public FileAccessI() throws IOException M<me\s)
{ 2QQYXJ^
this("",0); gB'Ah-@,P
} ]k%KTvX*G
[8(9.6f
=u1w\>(2Y
public FileAccessI(String sName,long nPos) throws IOException >w2WyYJYH
{ Ik2szXh[J
oSavedFile = new RandomAccessFile(sName,"rw"); J}`$WL:
this.nPos = nPos; 7QRvl6cv
oSavedFile.seek(nPos); ;@UX7NA
} hdWp
V,%5 hl'&
[(ib9_`A'1
public synchronized int write(byte[] b,int nStart,int nLen) +,w|&y
{ oXOO 10
int n = -1; /3HWP`<x
try{ pzp"NKxi
oSavedFile.write(b,nStart,nLen); $@!&ML
n = nLen; NNrZb?
} 61;5Yo
catch(IOException e) ]m,p3
{ ~.=!5Ry
e.printStackTrace (); 4BL,/(W] x
} LfSUY
%3B>1h9N
OX`GN#yl
return n; E MbI\=>yS
} F nRxc
dD2e"OIX
p{QKj3ov
} tTxo:+xg
B=xZkc
m!>'}z
/* #6Ph"\G/
**SiteInfoBean.java F476"WF
*/ DY27'`n6
package NetFox; |?Uc:VFF
`6F8Kqltr
\) ONy9
public class SiteInfoBean { R^C;D2
#SUq.A
v~=ol8J B
private String sSiteURL; //Site's URL @"5u~o')@v
private String sFilePath; //Saved File's Path f }e7g d]M
private String sFileName; //Saved File's Name ?Qp_4<(5
private int nSplitter; //Count of Splited Downloading File 25KZe s)
&BR?;LD
f}uCiV!?v
public SiteInfoBean() `Hu;Gdj=
{//nSplitter的缺省值为5 c8W=Is`
//default value of nSplitter is 5 tH!z7VZ
this("","","",5); PQ|x?98
} 7q1l9:VYE
PQay sdb
:CHd\."%+1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tq93 2M4
{ sZ$ ~abX
sSiteURL= sURL; eT?LMBn\
sFilePath = sPath; X;g|-<
sFileName = sName; ,~w)@.
this.nSplitter = nSpiltter; <C xet~x
0:S)2"I58p
Fje%hcV
} D/>5\da+y
$*ZHk0 7x
YiMecu
public String getSSiteURL() a#$%xw
{ zW.sXV,
return sSiteURL; l"#,O$x"#@
} EeJ]> 1
m#p^'}]!;
4'*K\Ul).H
public void setSSiteURL(String value) jz0\F,s
{ JASn\z
sSiteURL = value; ^)I:82"|?
} Rl8-a8j$f.
:r=_\?
o~ed0>D-LS
public String getSFilePath() } U.B$4Q
{ r8$TT\?~
return sFilePath; ozG:f*{T
} ,j<"~"] =
`$HO`d@0*R
!8].Z"5J
public void setSFilePath(String value) $Tza<nA
{ nm.d.A/]Z
sFilePath = value; +V^_ksi\
} 1g+<`1=KT
dQb?Zi7g
lB-7.
public String getSFileName() E83nEUs
{ 'cv/"26#
return sFileName; WDq3K/7\
} C/=ZNl9"fn
I6_+3}Hm{
*yx:nwmo
public void setSFileName(String value) YzqhFFaj.
{ vP!gLN]TV
sFileName = value; dmne+ufB
} !RI&FcK
q6dq@
q!4dK4`#5
public int getNSplitter() "]<Ut{Xb
{ F(9T;F
return nSplitter; wpdT "
} HO>uS>+
P%c<0y"O:>
eJ'ojc3
public void setNSplitter(int nCount) z; +x`i.
{ =z+zg^wsT
nSplitter = nCount; ?a% u=G
} Jx]`!dP3
} OA;L^d
;FUd.vg{
_F9 c.BH
/* 6 S8#[b
**Utility.java 4{TUoI6ii
*/ E+gUzz5
package NetFox; O;~1M3Ii
7K~=QEc
z|Xl%8
public class Utility { >}iYZ[ V
P7n~Ui~U
V>hy5hDpH
public Utility() hikun2
{ a)]N#gx
_<8n]0lX3
TUT>*
} y(HR1vQ;Z
WE3l*7<@
//线程睡眠 &\A$Rj)
public static void sleep(int nSecond) s<myZ T$
{ |cH\w"DcXw
try{ g)zy^aDf
Thread.sleep(nSecond); ?@ O[$9y
} $Iy>L.
catch(Exception e) KF.?b]
{ _\[Zr.y
e.printStackTrace (); ;fuy}q8@7
} ?D#Vha
} GYBM]mW^ W
`O[M#y%*E
//日志 R +k$_F
public static void log(String sMsg) mesR)fTI
{ 1:-$mt_*
System.err.println(sMsg); F](kU#3"S
} W>Zce="_gN
{pVD`#Tl[
`.n[G~*w~1
public static void log(int sMsg) !=a8^CV
{ bygwoZ<E
System.err.println(sMsg); X{)M}WO+r
} s3q65%D
} 419t"1b
-IPc;`<
)yjHABGJ
/* fPst<)
**TestMethod.java es.`:^A
*/ /0zk&g
package NetFox; Zcc6E2
7[Y<5T]
JTVCaL3Z
public class TestMethod { |g@1qXO3
/7*u!CNm
$L?stgU
public TestMethod() KnlVZn[3t
{ ///xx/weblogic60b2_win.exe tvI~?\Ylj
try{ )5hS;u&b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); % nJ'r?+h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fuQ?@F
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nhs]U`s(g
fileFetch.start(); 9^`G `D
} !IP[C?(nB
catch(Exception e){e.printStackTrace ();} HZR~r:_ i
>hHn{3y
Up`zVN59.
} Uc\\..Cf
I(pU_7mw
UA}k"uM
public static void main(String[] args) V+_L9
{ {4UlJ,Z.n
new TestMethod(); y2&G0y
} BH\qm (X
} H=EvT'g
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