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)); **[Z^$)u(
} X{-9FDW
for(int i=0;i<nEndPos.length-1;i++) 9OfFM9(:
{ =[<m[.)i
nEndPos = nStartPos[i+1]; g+C!kaC)
} S?0)1O
nEndPos[nEndPos.length-1] = nFileLength; :b,^J&~/)1
} N|2y"5
} Y3ZK%OyPR
J%]D%2vnk`
^5t
//启动子线程 Ut)r&?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2_t=P|Uo
for(int i=0;i<nStartPos.length;i++) 9(!]NNf!
{ -6Mm#sX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O8N[Jl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O;]?gj 1@
nStartPos,nEndPos,i); Sb:T*N0gS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vG2b:[W
fileSplitterFetch.start(); <39!G7ny
} lKEa)KF[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y#01o&f0n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kDz>r#%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wn11\j&
nEndPos = " + nFileLength); [W,-1.$!dM
// fileSplitterFetch[nPos.length-1].start(); n|4;Hn1V
hD<f3_k
XL}<1-}
//等待子线程结束 L6i|:D32p
//int count = 0; %E27.$E_
//是否结束while循环 ~-F?Mc
boolean breakWhile = false; 6bZ[Kt
#rYENR[
u; TvS |
while(!bStop) WIh@y2&R
{ p11G#.0
write_nPos(); Jll-X\O`-
Utility.sleep(500); \`xkp[C
breakWhile = true; ! ]Mc4!E
Z]:BYX'
u&TdWZe
for(int i=0;i<nStartPos.length;i++) $X+u={]
{ u:`y]
if(!fileSplitterFetch.bDownOver) g3?U#7i
{ ?4)v`*
breakWhile = false; r[Zq3
break; q?~Rnv
} ZcryAm:I
} $~'Tf>e
if(breakWhile) ?Cci:Lin
break; O(OmGu4%
n!N\zx8
(3EUy"z-
//count++; /b.oEGqZX
//if(count>4) Y&'8VdW
// siteStop(); 8HoP(+?
} qvLDfN
C 7nKk/r
!g0cC.'
System.err.println("文件下载结束！"); XSB8z
} ?(im+2
catch(Exception e){e.printStackTrace ();} amB@N6*
} \}inT_{g
+|C[-W7Sw
:J(sXKr[C
//获得文件长度 @PcCiGZ
public long getFileSize() nJVp.*S
{ {(vOt'
int nFileLength = -1; ,{j4
try{ +*t|yKO>[
URL url = new URL(siteInfoBean.getSSiteURL()); .T3=Eq&"W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z%v6xP.
httpConnection.setRequestProperty("User-Agent","NetFox"); jFj~]]j
vg5NY =O
B2hfD-h,>
int responseCode=httpConnection.getResponseCode(); P&t;WPZ
if(responseCode>=400) DcFCKji
{ i@$-0%,
processErrorCode(responseCode); *e<_; Kr?
return -2; //-2 represent access is error .u< U:*
} LC'2q*:'
( D}"&2
|@`"F5@,
String sHeader; *:arva5
:z~!p~
w4:<fnOM
for(int i=1;;i++) \X@IkL$r
{ XU#,Bu{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /Antb6E
//Utility.log(in.readLine()); .k]#XoE
sHeader=httpConnection.getHeaderFieldKey(i); z/vDgH!s
if(sHeader!=null) org*z!;.
{ r69WD .
if(sHeader.equals("Content-Length")) 9oq)X[
{ 5V|tXsy:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *j<@yG2\gP
break; O:u%7V/
} #,P(isEZ"
} HIPL!ss]
else 6`"ZsO
break; `D)S-7BR
} 5<r)+?!n
} ?-{IsF^
catch(IOException e){e.printStackTrace ();} .cw=*<zeg
catch(Exception e){e.printStackTrace ();} eG^z*`**
aL$j/SC
/'+4vXc@
Utility.log(nFileLength); Y~GUR&ww0n
s=\7)n=,M
nh|EZp]
return nFileLength; *dVD
} c'lIWuL)
P6E1^$e
htg'tA^CtS
//保存下载信息（文件指针位置） ./)j5M
private void write_nPos() a^*B5G1(&
{ T]X{@_
try{ ZE ^u.>5
output = new DataOutputStream(new FileOutputStream(tmpFile)); \#_@qHAG
output.writeInt(nStartPos.length); Deog4Ol"/
for(int i=0;i<nStartPos.length;i++) K*[0dza$
{ rUvwpP"k
// output.writeLong(nPos); ;y,NC2Xj
output.writeLong(fileSplitterFetch.nStartPos); FP@A;/c
output.writeLong(fileSplitterFetch.nEndPos); _3zU,qm+
} Obg@YIwn
output.close(); 4Q/r[x/&C
} z,os MS
catch(IOException e){e.printStackTrace ();} ev*c4^z:s
catch(Exception e){e.printStackTrace ();} >T(M0Tkt
} Cea"qNq=k
4&H+hN{3
mf#fA2[
//读取保存的下载信息（文件指针位置） TR|;,A[%v#
private void read_nPos() 3lyQn"
{ |M]sk?"^
try{ 6WCmp,*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .!!79 6hS
int nCount = input.readInt(); dzpj9[
nStartPos = new long[nCount]; 0%#t[usY
nEndPos = new long[nCount]; h#vL5At
for(int i=0;i<nStartPos.length;i++) Z<w,UvJa
{ fdg[{T4:
nStartPos = input.readLong(); ,&-S?|
nEndPos = input.readLong(); wYC9~ms-
} 9Zs#Ky/
input.close(); 5 1v r^
} Cl%V^xTb
catch(IOException e){e.printStackTrace ();} 1 VPg`+o
catch(Exception e){e.printStackTrace ();} Y#GT*V
} 6R0D3kW
R>^5$[
4+BrTGp
private void processErrorCode(int nErrorCode) pq%t@j(X
{ &8R-C[A
System.err.println("Error Code : " + nErrorCode); ;:-}z.7Y
} Oz_b3r
<m-Ni
wOD/Z8
//停止文件下载 Ky=(urAd
public void siteStop() s{b0#[
{ /<(R
bStop = true; TG""eC!E
for(int i=0;i<nStartPos.length;i++) X`8Y[Vb3}
fileSplitterFetch.splitterStop(); yz54:q?
O e0KAn
y}3 `~a
} EU`' 8*4
} c80"8r
//负责部分文件的抓取 ,C5@P+A
**FileSplitterFetch.java g)2m$#T&s
*/ .&aVx]
package NetFox; e7)>U!9c9
iPRJA{$b_
4nX'a*'D~}
import java.io.*; 3hp tP
import java.net.*; o.v,n1Nm
C.B8 J"T-
>2!^ dT^D
public class FileSplitterFetch extends Thread { SLbavP#G
+btP]?04
T%z!+/=&^
String sURL; //File URL gK]T}
long nStartPos; //File Snippet Start Position [kU[}FT
long nEndPos; //File Snippet End Position 5d!z<{`
int nThreadID; //Thread's ID '6Rs0__
boolean bDownOver = false; //Downing is over C5W-B8>
boolean bStop = false; //Stop identical b*$o[wO9
FileAccessI fileAccessI = null; //File Access interface F~11 _
RMs1{64:
r;5 AY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d@`-!"
{ SO8|]Fk
this.sURL = sURL; }&'yt97+
this.nStartPos = nStart; k_.j%
this.nEndPos = nEnd; wE.@0
nThreadID = id; &El[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '<U[;H9\
} +eH=;8
N-_| %C-.
_3g %F
public void run() C$EFh4
{ j+ T\c2d
while(nStartPos < nEndPos && !bStop) Q'V,?#
{ I$sm5oL
j4hUPL7
!&:.Uh
try{ ~(L<uFU V
URL url = new URL(sURL); I n%yMH8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yW7S }I
httpConnection.setRequestProperty("User-Agent","NetFox"); '$&(+>)z`
String sProperty = "bytes="+nStartPos+"-"; 3 %{'Uh,
httpConnection.setRequestProperty("RANGE",sProperty); (Su2\x
Utility.log(sProperty); 9\;/-0P
"{1}
Zm'::+tl
InputStream input = httpConnection.getInputStream(); MLDg).5
//logResponseHead(httpConnection); &JzF
=u1w\>(2Y
5v03<m0`y
byte[] b = new byte[1024]; B7^n30+L
int nRead; Xf/<.5A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;`Ch2b1+
{ _-2n3py
nStartPos += fileAccessI.write(b,0,nRead); Vste$V
//if(nThreadID == 1) 2nz'/G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o\Vt $
} rcb/X`l=
T;e(Q,!H
XzwQ,+IAr
Utility.log("Thread " + nThreadID + " is over!"); $@!&ML
bDownOver = true; (E]K)d
//nPos = fileAccessI.write (b,0,nRead); YedipYG9;
} ]m,p3
catch(Exception e){e.printStackTrace ();} mI*>7?
} [==Z1Q;=
} !ZcALtq
!ef)Ra-W
2PW3S{Dt
//打印回应的头信息 ^mb*w)-p?
public void logResponseHead(HttpURLConnection con) 5rSth.&
{ 43]&SXprH
for(int i=1;;i++) !a&F:Fbm
{ dfd%A" I
String header=con.getHeaderFieldKey(i); `SbX`a0p2
if(header!=null) zL{@LHP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q&\ksM
Utility.log(header+" : "+con.getHeaderField(header)); "N"k8,LH
else s'w0pZqj
break; r>eXw5Pr7
} a{6|[aR
} mTbPzZ4
R-|]GqS}L
P"VLGa
public void splitterStop() AV`7>@
{ _!vbX mb
bStop = true; T8oASg!
} JFkjpBS
aDEP_b;
'Z}$V*
} HAdm,
j>M%?Tw
FkkB#Jk4
/* 0`=?ig_
**FileAccess.java $~\qoW<
*//文件访问(定位，写) c9k,Dc
package NetFox; B75SLK:h=
import java.io.*; c9={~
Q&;qFv5-l
T!E LH!
public class FileAccessI implements Serializable{ (9%%^s]uPT
sP8B?Tn1W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^9E(8DD
RandomAccessFile oSavedFile; o%7yhCY
long nPos; ?2Dz1#%D
Kj5f:{Ur
] lTfi0}g_
public FileAccessI() throws IOException YiMecu
{ \rO>FE
this("",0); J'v|^`bE
} 3E9j%sYk
CAO{$<M5m
;c}];ZU3G
public FileAccessI(String sName,long nPos) throws IOException +r"$?bw'
{ lvffQ_t
oSavedFile = new RandomAccessFile(sName,"rw"); =Q/i<u
this.nPos = nPos; exvsf|
oSavedFile.seek(nPos); upKrr
} #nz$RJsX
3~'F^=T.Y
85]UrwlA4
public synchronized int write(byte[] b,int nStart,int nLen) vZsVxx99
{ <Z[R08 k
int n = -1; 4[wP$
try{ #a:C=GV;4
oSavedFile.write(b,nStart,nLen); N<%,3W_-_
n = nLen; :Tl?yGF
} N<WFe5
catch(IOException e) L1BpY-=
{ 'z:p8"h}
e.printStackTrace (); b.+\qaR
} egvWPht'_
9IV WbJ
?i"FdpW
return n; gw^+[}U#
} ~E~J*R Ze
^DOcw@Z6HC
FW,D\51pTP
} sjGZ ,?%
7\lb+^$
cCs:z
/* WBIS
**SiteInfoBean.java RCr:2 Iz
*/ i:72FVo
package NetFox; 8!fwXm
,5,4Qf7
d8I/7 ;F X
public class SiteInfoBean { }z#8vE;
'cv/"26#
bcG-js-
private String sSiteURL; //Site's URL ai RNd~\
private String sFilePath; //Saved File's Path ~r3g~MCHS
private String sFileName; //Saved File's Name E%N]t} }[
private int nSplitter; //Count of Splited Downloading File q)X&S*-<o~
oxZ(qfjS
WP9=@X Z
public SiteInfoBean() :C5N(x
{//nSplitter的缺省值为5 +Gko[<
//default value of nSplitter is 5 4(]k=c1<
this("","","",5); ikC;N5Sw
} 8*X8U:.0o
T7`Jtqf
c-F&4V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >8so'7(
{ YuZnuI@m9
sSiteURL= sURL; @B6[RZR
sFilePath = sPath; [sBD|P;M
sFileName = sName; _=b[b]Ec$s
this.nSplitter = nSpiltter; <G={Vfr
aryr
ak zb<aT
} eJ'ojc3
jiat5
d {4br
public String getSSiteURL() dj#<,e\
{ o<y7Ut
return sSiteURL; .?qS8:yA
} Jx]`!dP3
U\N`[k.F
bZ)Jgz
public void setSSiteURL(String value) ;FUd.vg{
{ n"JrjvS
sSiteURL = value; WW.=>]7;
} 2rk_ ssvs
z3,z&Ra
%PpB$
public String getSFilePath() Yi:+,-Fso
{ qXW5_iX
return sFilePath; P;GUGG*W
} chy7hPxC;
)u$A!+fo
N.]8qzW
public void setSFilePath(String value) =B\?(
{ hn-S$3')`
sFilePath = value; ]Q+Tm2{
} <_5z^@N3$
?AEpg.9R-
)9$Xfq/
public String getSFileName() ;]gph)2cd
{ rv+"=g
return sFileName; Z`D#L[z$
} VH/_0
I'";
u}$?r\H'(
public void setSFileName(String value) C..O_Zn{g
{ yR&E6o.$z
sFileName = value; "2)T=vHi#
} \6o ~ i
d%<Uh(+:
W\"cp[b
public int getNSplitter() B}vI<?c
{ q8U]Hyp(`
return nSplitter; \(Iy>L.
} 3KGDS9I
u+*CpKR}
yuND0,e
public void setNSplitter(int nCount) 3E#acnqn*
{ (g 8K?Q
nSplitter = nCount; ?/;<32cE,
} &{$\]sv
} {_ocW@@
J4<- C\=4
`Tab'7
/* [p(Y|~
**Utility.java ~ 60J
*/ ]5^u^
package NetFox; "ey~w=B$M
DpA)Z??
1iUy*p65:
public class Utility { BQm H9g|2
T =:^k+
E|No$QO)
public Utility() I)6)~[:'
{ %f@]-
bygwoZ<E
"UE'dWz
} UXd\Q''
pJ{sBp_$
//线程睡眠 _:{XL c
public static void sleep(int nSecond) N-suBRnW
{ q*2ljcb55
try{ il*bsnwpZv
Thread.sleep(nSecond); h4V.$e<T&
} c|E
catch(Exception e) k1X<jC]P
{ rXA7<_Vg
e.printStackTrace (); {1FYHM^
} R!:1{1
} k+&|*!j
%hY+%^k.
//日志 }lhJt|qc
public static void log(String sMsg) /q8n_NR
{ F$)Ki(mq
System.err.println(sMsg); t.NG]ejZ
} J|s4c`=
#bnFR
/QTGZb
public static void log(int sMsg) ~dC^|
{ $AoN,B>
System.err.println(sMsg); =\tg$
} % nJ'r?+h
} _,5(HETE2
p3X>
qV5ME#TJ
/* ZYg="q0x&
**TestMethod.java r3#H]c
*/ VaH#~!
package NetFox; Fe:0nr9;
=8[HC}s|$
aVd{XVE
public class TestMethod { ~W!sxM5(*
LTrn$k3}
O0wD"V^W
public TestMethod() }nuhLt1
{ ///xx/weblogic60b2_win.exe X|X6^}
try{ o: TO[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y!!p:3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Aj-}G^>#
SiteFileFetch fileFetch = new SiteFileFetch(bean); W*gu*H^s~
fileFetch.start(); je.mX/Lpj
} JIDE]f
catch(Exception e){e.printStackTrace ();} +.{_n(kU
C%l~qf1n
Rom|Bqo;
} BB9Z?}
Aqq%HgY:t
\S3C"P%w
public static void main(String[] args) IeE+h-3p
{ eo"6 \3z
new TestMethod(); l1a=r:WhH
} v@[MX- ,8
} Z{&PKS
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