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)); l,5<g-r V
} l+g\xUP
for(int i=0;i<nEndPos.length-1;i++) A<-Prvryt
{ +iKs)s_~
nEndPos = nStartPos[i+1]; r;m_@*]
} V8AF;1c?-'
nEndPos[nEndPos.length-1] = nFileLength; CZaUrr
} evOyTvc
} qOOF]L9r%u
{hYH4a&Hb
4pNIsjl}
//启动子线程 1UG5Q-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p4mlS
for(int i=0;i<nStartPos.length;i++) -XNjyXm2
{ {KkP"j'7h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V}<Hx3!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P>q"P1&{
nStartPos,nEndPos,i); `\!oY;jk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R&Mv|R
fileSplitterFetch.start(); .<uxZ
} )c~1s
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /HCd52
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rw>X JE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IO/%X;Y_
nEndPos = " + nFileLength); 9gFb=&1k
// fileSplitterFetch[nPos.length-1].start(); pdCn98}%-
&%3$zgvR
Fl)p^uUtl
//等待子线程结束 f%r0K6p
//int count = 0; [>+}2-#
//是否结束while循环 V^Gz7`^
boolean breakWhile = false; Th1/Bxb:
15PFnk6E|
l"9.zPvT<
while(!bStop) qbu>YTj
{ }py6H[
write_nPos(); [X>\!mt
Utility.sleep(500); $@]tTz;b
breakWhile = true; _m3}0q
ch2Qk8
H(f~B<7q
for(int i=0;i<nStartPos.length;i++) rzmd`)g
{ (pY'v/a-
if(!fileSplitterFetch.bDownOver) FtBYPSGz
{ "{a-I=s\C
breakWhile = false; Vy*&po[
break; X;$g7A
} 0}'
} m|mY_t
if(breakWhile) V/%tFd1
break; :W]IJ mI\
HzADz%~
\;w$"@9
//count++; ^H]q[XFR
//if(count>4) F3k]*pk8w
// siteStop(); d)V"tSC,
} NyHHK8>
Z:F5cXt<
%C&HR2
System.err.println("文件下载结束！"); `LD#fg*
} 8S;]]*cD~
catch(Exception e){e.printStackTrace ();} ;O8Uc&:P
} m e\S:
G)qNu}
:=J~t@
//获得文件长度 w[g(8#*
public long getFileSize() yO@KjCv"
{ m~KGB"
int nFileLength = -1; w]n ,`r^
try{ ,SEC~)L
URL url = new URL(siteInfoBean.getSSiteURL()); G/Ll4 :
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B+e$S%HV
httpConnection.setRequestProperty("User-Agent","NetFox"); u$T`Bn
3&*_5<t\X
"YIrqk
int responseCode=httpConnection.getResponseCode(); \;"$Z9W
if(responseCode>=400) Bvbv~7g(
{ z'cK,psq(
processErrorCode(responseCode); }jj@A !N
return -2; //-2 represent access is error S@Rw+#QE
} -w8c;5X
\5g7_3,3W
%;5AF8#c
String sHeader; ^T}6oUd
&zVF!xNy&
*.g0;\HF
for(int i=1;;i++) B o@B9/ABv
{ }1EfyR
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UzLe#3MU
//Utility.log(in.readLine()); JzhbuWwF-
sHeader=httpConnection.getHeaderFieldKey(i); :Ja]Vt
if(sHeader!=null) dV{N,;z
{ M>Yge~3
if(sHeader.equals("Content-Length")) 1$cX`D`
{ D9OI",h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "wk~[>
break; u_0&`zq
} &[]0yNG
} Fi8'3/q-^
else OKDBzl
break; Vq7L:,N9
} &r0b~RwUv
} ~N</;{}fL4
catch(IOException e){e.printStackTrace ();} L%D:gy9o
catch(Exception e){e.printStackTrace ();} eBZ^YY<*g
hdFIriE3
m%8idjnG
Utility.log(nFileLength); -#yLH
eK }AVz}k
vfW
return nFileLength; *0y|0J+0
} }=kf52Am,}
=M]f7lJ
D@[Mk"f
//保存下载信息（文件指针位置） d1=kHU4_9
private void write_nPos() !1MSuvWP
{ MGUzvSf
try{ 7 S^iGe
output = new DataOutputStream(new FileOutputStream(tmpFile)); +-=o16*{ !
output.writeInt(nStartPos.length); p h[ ^ve
for(int i=0;i<nStartPos.length;i++) 3U#z {%
{ \/8 I6a=
// output.writeLong(nPos); 9v7l@2/
output.writeLong(fileSplitterFetch.nStartPos); *G{%]\s?
output.writeLong(fileSplitterFetch.nEndPos); ?t LJe
} h> K~<BAz'
output.close(); IvLo&6swW
} CTu#KJ?j
catch(IOException e){e.printStackTrace ();} }F=+*-SYZ
catch(Exception e){e.printStackTrace ();} a<CN2e_Z
} "^A4!.
fJ!i%</V
d8 1u
//读取保存的下载信息（文件指针位置） x"kc:F
private void read_nPos() uo`O$k<;
{ bv&A)h"S
try{ }t4?*:\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fFG, ^;7-O
int nCount = input.readInt(); `N0Mm7
nStartPos = new long[nCount]; 'n>,+,&
nEndPos = new long[nCount]; L4th 7#
for(int i=0;i<nStartPos.length;i++) ]fH U/%
{ "*o54z5"
nStartPos = input.readLong(); y(M-
nEndPos = input.readLong(); e/@tU'$
} )9sRDNr
input.close(); & i,on6
} i#I+
catch(IOException e){e.printStackTrace ();} hdB.u^!
catch(Exception e){e.printStackTrace ();} ?`+46U%
} P.bBu
klC;fm2C
["|' f
private void processErrorCode(int nErrorCode) `I$'Lp#5
{ =3rPE"@,[
System.err.println("Error Code : " + nErrorCode); oiP8~
} \I r&&%
y~)rZ-eSB
Eq>3|(UT
//停止文件下载 w_30g6tA
public void siteStop() ]w!gv /;
{ =2HR+
bStop = true; }]w/`TF
for(int i=0;i<nStartPos.length;i++) N>z<v\`
fileSplitterFetch.splitterStop(); b2;+a(
k/+-Tq;
u|m>h(O
} tB"amv
} ZKKz?reM'
//负责部分文件的抓取 G{*m] 0Q
**FileSplitterFetch.java bH}6N>Fp
*/ +^% y&8e
package NetFox; ns_5|*'
!6_lD0
:>gzWVE<
import java.io.*; dI!x Ai
import java.net.*; @=o1q=5@8
Q9X7-\n
bSmF"H0cP
public class FileSplitterFetch extends Thread { FY%v \`@1*
i3I'n*
XGE:ZVpW
String sURL; //File URL g0ec-
long nStartPos; //File Snippet Start Position @NMFurm
long nEndPos; //File Snippet End Position p"4i(CWGS
int nThreadID; //Thread's ID k$</7IuH
boolean bDownOver = false; //Downing is over ra\Moy
boolean bStop = false; //Stop identical mG[S"?C
FileAccessI fileAccessI = null; //File Access interface j I
tjZ.p.IlG
%)[mbb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %MyA;{-F6
{ @MIBW)P<
this.sURL = sURL; jRN*W2]V
this.nStartPos = nStart; 0raVC=[
this.nEndPos = nEnd; UkrqHHpy
nThreadID = id; W69 -,w/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l,Un7]*
} JpN]j`
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public void run() &.ZW1TxE8
{ D$g|f[l
while(nStartPos < nEndPos && !bStop) $M\|zUQu.
{ iTgGf
j""I,$t
)5Yv7x(K
try{ Z5juyzj
URL url = new URL(sURL); 7sECbbJT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Cxh>,k
httpConnection.setRequestProperty("User-Agent","NetFox"); "Y@rNmBj
String sProperty = "bytes="+nStartPos+"-"; &Im{p7gf!b
httpConnection.setRequestProperty("RANGE",sProperty); ")|3ZB7>*
Utility.log(sProperty); m7X&"0X
j:D@X=|
QC.WR'.
InputStream input = httpConnection.getInputStream(); p2}$S@GD
//logResponseHead(httpConnection); <,qJ%kc
dzDh V{
ia15r\4j)
byte[] b = new byte[1024]; <{@?c
int nRead; )@.bkzW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Tyu]14L
{ 7kU:91zR
nStartPos += fileAccessI.write(b,0,nRead); Ko6tp9G
//if(nThreadID == 1) Z qX U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fq/F|c
} %]%.{W\j3
\&\_[y8U
v{Cts3?Br
Utility.log("Thread " + nThreadID + " is over!"); }$u]aX<
bDownOver = true; 0S@O]k)
//nPos = fileAccessI.write (b,0,nRead); \KfngYD]W
} \3dMA_5
catch(Exception e){e.printStackTrace ();} KZO!
} ~Nf01,F
} \dj&4u3
AfKJaDKf
~[XDK`B
//打印回应的头信息 2<}^m/}
public void logResponseHead(HttpURLConnection con) v 1Yf:c
{ cSCO7L2E18
for(int i=1;;i++) .58>KBj(
{ FRI<A8
String header=con.getHeaderFieldKey(i); $Ch!]lJA
if(header!=null) 8[(eV.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E>Ukxi1
Utility.log(header+" : "+con.getHeaderField(header)); )t={+^Xe
else kvs^*X''Ep
break; \&]M \
} Db\.D/76
} 2%0zPflT
v :]y#y
7uJy<O
public void splitterStop() kXS_:f;M
{ lZCvH1&"
bStop = true; Nj||^k
} LNml["
p,}-8#K[
^_3idLE
} x!bFbi#!"
?KpHvf'
!o~% F5|t
/* V1Dwh@iS
**FileAccess.java (:E_m|00;
*//文件访问(定位，写) y %Get
package NetFox; %)*!(%\S*3
import java.io.*; W"4E0!r
{EbR =
)hj77~{+
public class FileAccessI implements Serializable{ ,(Fo%.j
SQ5SvYH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /_v5B>
RandomAccessFile oSavedFile; !zLd,`
long nPos; s$6zA j!
dluNA(Xc-
T8>:@EL-k
public FileAccessI() throws IOException |$Dt6{h
{ h8>7si
this("",0); u7G@VZ Ux5
} 'vj45b
L?&+*|VxI
.Tt \U
public FileAccessI(String sName,long nPos) throws IOException k\|G%0Jw
{ <aa#OX
oSavedFile = new RandomAccessFile(sName,"rw"); Nkn0G_
this.nPos = nPos; 4q[C' J
oSavedFile.seek(nPos); E+V^5Z:u
} rklr^ e
3;~1rw=$<
x*}j$n(Oa
public synchronized int write(byte[] b,int nStart,int nLen) {YWj`K
{ S%uH*&`
int n = -1; sR,]eo<p&
try{ qu BTRW9
oSavedFile.write(b,nStart,nLen); Lx,"jA/
n = nLen; l5Z=aW Q
} 0!veLXeK!
catch(IOException e) zkn K2e,$
{ AuUT 'E@E
e.printStackTrace (); w_pEup\`
} 4>>{}c!nf
'|&}rLr:+
w{)*'8oCB
return n; f!ehq\K1k
} 3 8pw
kW\=Z1\#
?XL[[vyr
} Ya*lq! u
lxj_(Uo
nH}api^0A
/* b>;>*'e
**SiteInfoBean.java QE84l
*/ (G<"nnjK
package NetFox; N72z5[..
85$MHod}[,
pBiC
public class SiteInfoBean { [J\5DctX;c
9_JK.
'VFxg,
private String sSiteURL; //Site's URL *CA|}l
private String sFilePath; //Saved File's Path l"RX`N@In
private String sFileName; //Saved File's Name H`]nY`HYg
private int nSplitter; //Count of Splited Downloading File hJ.XG<?]$
vmJ1-<G4*
~6.AE/ow
public SiteInfoBean() fF[n?:VV
{//nSplitter的缺省值为5 |TF,Aj
//default value of nSplitter is 5 \D?6_ ,O
this("","","",5); f}^}d"&F
} 3!Zd]1$
^~-i>gTD
&WN4/=QW-J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]0by6hQ
{ cf1Ve\(YGI
sSiteURL= sURL; .3qaaXeH
sFilePath = sPath; suj? e6
sFileName = sName; 3ag*dBbs
this.nSplitter = nSpiltter; 'e02rqip{
HKv:)h{?
QW6F24
} l-_voOP
QXishHk&
v3Tr6[9
public String getSSiteURL() f3lFpS
{ <i^Bq=E<rJ
return sSiteURL; N\=pH{
} 5!}xl9D
pA"x4\s
|4YDvDEJi
public void setSSiteURL(String value) :N\*;>
{ !cE>L~cza
sSiteURL = value; kLR4?tX!
} @YdS_W
.a:"B\B`
\E9Z H3;
public String getSFilePath() Zw| IY9D
{ 6(sqS~D
return sFilePath; yU\&\fD>j
} \MsAdYR
.oH0yNFX
u@}((V
public void setSFilePath(String value) T=:O(R1*0
{ \:8~na+(
sFilePath = value; /tc*jXB
} dn$1OhN8M
p&B98c
&zlwV"W
public String getSFileName() UA>~xJp=
{ 6/hY[a!
return sFileName; i&-g 0
} @}!1Uk3ud
{#:js
upQ:C>S
public void setSFileName(String value) T.d+@ZV<#
{ Q7&Yy25
sFileName = value; uaNJTob
} {\ P$5O{%
W)1)zOD
apa~Is1
public int getNSplitter() 7S7gU\qOj
{ /S$p_7N
return nSplitter; <(6@l@J|6
} vI{JBWE,S
W tnZF]1:u
.UakO,"z
public void setNSplitter(int nCount) 1s-k=3)
{ x6* {@J&5*
nSplitter = nCount; kCL)F\v"iT
} T_\HU*\
} N)lzX X
$@FD01h.t3
2JYp.CJv
/* 4wX{N
**Utility.java mwZesSxB_
*/ XPd>DH(Yc
package NetFox; `i8osX[&p
eU1= :n&&\
nj!)\U
public class Utility { ~7Kqc\/H&I
r*N:-I~z
=#&K\
public Utility() ?xGxr|+a
{ 4 `Z@^W
pB@8b$8(Z
}.3F|H
} _J}ce
L=iaL[zdJ
//线程睡眠 +)^F9LPl
public static void sleep(int nSecond) A5!jrSyv
{ :J@q Xa
try{ muQH!Q
Thread.sleep(nSecond); 8js5/G+
} Z=sy~6m+v
catch(Exception e) $R2T)
{ ta> g:
e.printStackTrace (); Dp6]!;kx
} gd]vrW'wj
} 2*vOo^f
VjtI1I
//日志 }IC$Du#
public static void log(String sMsg) r[vMiVb
{ X, <&#l
System.err.println(sMsg); W=j/2c/
} wp-5B= #:{
)pjd*+V
;o,t*
public static void log(int sMsg) $Tfq9
{ Vl{CD>$,
System.err.println(sMsg); y<m{eDV7
} S6B(g_D|
} k;3Bv 6
=$}P'[V
b=9(gZ 9
/* |VB}Kv
**TestMethod.java }9R45h}{<
*/ nZfTK>)A0
package NetFox; l$z[Vh^UU<
Ms<^_\iPN
.LEQ r)
public class TestMethod { Bz_['7D
1.o-2:]E
s{NEP/QQJ
public TestMethod() p)f OAr
{ ///xx/weblogic60b2_win.exe >@[`,
try{ qBpv[m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [@"H2#CQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?;0=>3p*0
SiteFileFetch fileFetch = new SiteFileFetch(bean); g:q+.6va"
fileFetch.start(); n>Y3hY
} RsIEY5Q
catch(Exception e){e.printStackTrace ();} Q nDymVF
q =b.!AZy
/_rQ>PgSZW
} (s %T18
i92{N$*x
&jl'1mZ
public static void main(String[] args) :@wO' o
{ iH9g5G`O
new TestMethod(); $N5VoK
} k)'hNk"x
} iv?'&IUfK
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