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)); y]@JkF(
} I(R%j]LX&
for(int i=0;i<nEndPos.length-1;i++) \)uA:v
{ 6}R*7iMs
nEndPos = nStartPos[i+1]; Qm3F=*)d
} d]sqj\Q57
nEndPos[nEndPos.length-1] = nFileLength; -n|>U:
} AzJ;EtR
} o[Qb/ 7
GP4!t~"1
r?[[.zm"7
//启动子线程 ^TZmc{i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hL/u5h%$
for(int i=0;i<nStartPos.length;i++) Rf`_q7fm
{ %b*N.v1+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M-h+'G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kI(3Pf].
nStartPos,nEndPos,i); /YZMP'v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;[ Dxk$"
fileSplitterFetch.start(); iQ Xlz]'
} Yn [ F:Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {c3FJ5:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /Q7q2Ne^*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", aG;F=e
nEndPos = " + nFileLength); H:hM(m0?q
// fileSplitterFetch[nPos.length-1].start(); Dmi.@.
ZHZxr
qVfn(rZ
//等待子线程结束 HM)D/CO,?
//int count = 0; |z3!3?%R
//是否结束while循环 ,|yscp8
boolean breakWhile = false; ;Z0&sFm
O0'|\:my
O6?{@l
while(!bStop) IYq#|^)5+
{ R3og]=uFzm
write_nPos(); AC <2.i_
Utility.sleep(500); U{ 0~&
breakWhile = true; a"YVr'|
9jf9u0
V]J"v#!{
for(int i=0;i<nStartPos.length;i++) D<FQVdP
{ WynTU?
if(!fileSplitterFetch.bDownOver) .F@Lx45
{ #'KM$l,P
breakWhile = false; Jy}~ZY
break; h9m|f|cH
} c"kB@P
} %E@o8
if(breakWhile) m_Ed[h/I
break; tik*[1it
| WJ]7C
\PT!mbB?
//count++; hY{4_ie=8
//if(count>4) 53aJnxX
// siteStop(); k?Hi_;o
} LvS5N)[
3xW:"
B=]L%~xL$
System.err.println("文件下载结束！"); f@ |[pT
} %Bm{ctf#)
catch(Exception e){e.printStackTrace ();} k]:`<`/I_
} ".|8(Y
` ~m/
lU Zj
//获得文件长度 T7mT:z>:
public long getFileSize() m[y~-n
{ Gev\bQa
int nFileLength = -1; p#4*:rpq4
try{ |=:@<0.'
URL url = new URL(siteInfoBean.getSSiteURL()); X:`=\D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bQI :N
httpConnection.setRequestProperty("User-Agent","NetFox"); /cdLMm:
8wd["hga<%
9+m>|"F0
int responseCode=httpConnection.getResponseCode(); |7,$.MK-@
if(responseCode>=400) 1&e8vVN
{ ]!S#[Wt {k
processErrorCode(responseCode); }03?eWk/y
return -2; //-2 represent access is error <!G /&T
} sdCG}..`
V}<<?_
9=iMP~?xF
String sHeader; d!<>Fh^6,
W?E01"p
y=\&z&3$
for(int i=1;;i++) Oz\J+
{ ,)\G<q yO6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9(HGe+R4o
//Utility.log(in.readLine()); @+M1M2@Xz
sHeader=httpConnection.getHeaderFieldKey(i); ]g9SUFM
if(sHeader!=null) q'H6oD`
{ R6 ej
if(sHeader.equals("Content-Length")) 7ZAxhFC
{ YG*<jKcX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6v:L8t$"
break; *wqR.n?
} xG edY*[`
} GBg
else aDz% %%:r
break; +ah4 K(+3
} -ys/I,}<
} #gWok'ZcR
catch(IOException e){e.printStackTrace ();} R$}Hv
catch(Exception e){e.printStackTrace ();} D8w.r"ne
`xv Uq\
>J;J&]Olf
Utility.log(nFileLength); lws.;abm%n
!}P^O(oY
@/As|)
return nFileLength; D.7cWR`Wp
} (K6vXq.;\\
A6_ER&9$>N
N!?~Dgw
//保存下载信息（文件指针位置） %CQa8<q
private void write_nPos() gJwX
{ UjunIKX+
try{ NA@Z$Gy
output = new DataOutputStream(new FileOutputStream(tmpFile)); c+ZdfdR
output.writeInt(nStartPos.length); #]i^L;u1A
for(int i=0;i<nStartPos.length;i++) jZ5ac=D&I
{ \Qnr0t@0
// output.writeLong(nPos); 2|exY>`w
output.writeLong(fileSplitterFetch.nStartPos); mBrZ{hqS
output.writeLong(fileSplitterFetch.nEndPos); 4>Ht_B<<
} !F6rcDKI
output.close(); m>[G-~0?kI
} "\9beK:l
catch(IOException e){e.printStackTrace ();} B"4A1!
catch(Exception e){e.printStackTrace ();} "3 2Ua3m:G
} WQw11uMt@q
r#ADxqkaV
%|/\Qu
//读取保存的下载信息（文件指针位置） ""V\hHdp
private void read_nPos() ~Odclrs
{ &BKnJ{,H
try{ VWXyN
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gQhYM7NP{5
int nCount = input.readInt(); C)qG<PW.!
nStartPos = new long[nCount]; 60|m3|0o
nEndPos = new long[nCount]; ^N ;TCn
for(int i=0;i<nStartPos.length;i++) GmUm?A@B
{ {KTZSs $n
nStartPos = input.readLong(); hQzT =0
nEndPos = input.readLong(); o4rf[.z
} !L|VmLqa
input.close(); CIwI1VR^
} W>x.*K
catch(IOException e){e.printStackTrace ();} Bz,Xg-k+
catch(Exception e){e.printStackTrace ();} QRdtr
} z:Ru`
(i<\n`h1K
==KDr0|G
private void processErrorCode(int nErrorCode) VL\Ah3+
{ Y?oeP^V'u
System.err.println("Error Code : " + nErrorCode); 2I=4l
} )h(=X&(d
KxJDAP
|a0@4 :
//停止文件下载 WT 5 2
public void siteStop() tC+11M
{ "0>AefFd#
bStop = true; 6lr<{k7Nw
for(int i=0;i<nStartPos.length;i++) 6: R1jF*eG
fileSplitterFetch.splitterStop(); r5lPO*?Df
Fkqw#s(T
Aba%QQQ
} z+_d*\
} "[_gRe*2
//负责部分文件的抓取 !a%_A^t7
**FileSplitterFetch.java =jG."o
*/ )ZZ6 (O
package NetFox; K[V#Pj9
gZz5P>^
|hvclEu,
import java.io.*; xf:|lQf
import java.net.*; +9;6]4
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EUPc+D3
public class FileSplitterFetch extends Thread { e/)Vx'd`+
1B{u4w7S4e
oSR;Im<2
String sURL; //File URL sw(|EZ7F
long nStartPos; //File Snippet Start Position H7{kl
long nEndPos; //File Snippet End Position }mk z_P(Z
int nThreadID; //Thread's ID IS{>(XT{
boolean bDownOver = false; //Downing is over *MCkezW7{
boolean bStop = false; //Stop identical tg2+Z\0)4g
FileAccessI fileAccessI = null; //File Access interface kf' 4C "}
0}>p)k3&A
!|,djo!N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *u>[
{ =@;\9j
this.sURL = sURL; -{*QjP;K
this.nStartPos = nStart; NdI~1kemr
this.nEndPos = nEnd; k#5Qwxu`
nThreadID = id; &x[V<Gq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9$R}GK
} %$R]NL|
Uo:=-NNI
ukee.:{
public void run() -zm-|6[Wi
{ \-Q6z8
while(nStartPos < nEndPos && !bStop) NF*Z<$'%
{ 40;4=
<q4<3A
V9D>Xh!0H
try{ ,V+,3TT
URL url = new URL(sURL); j;&su=p"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {9./-
httpConnection.setRequestProperty("User-Agent","NetFox"); /yO0Z1G
String sProperty = "bytes="+nStartPos+"-"; H$3:Ra+ S
httpConnection.setRequestProperty("RANGE",sProperty); 7Rr +Uzb(
Utility.log(sProperty); $r(9'm}W
~Y7:08
J}VG4}L
InputStream input = httpConnection.getInputStream(); ]n4G]ybK%
//logResponseHead(httpConnection); 5mI}IS|@
t "[2^2G
}}d,xI
byte[] b = new byte[1024]; lM%3 ?~?Q&
int nRead; KN\tRE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T5TAkEVl
{ +78cQqDY!
nStartPos += fileAccessI.write(b,0,nRead); 2Ni {fC?
//if(nThreadID == 1) :T/I%|;f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kfs[*ku
} yT C+5_7
Wtj*Z.=:
bR83N
Utility.log("Thread " + nThreadID + " is over!"); B d?{ldg
bDownOver = true; >+ku:<Hw%.
//nPos = fileAccessI.write (b,0,nRead); 1xb1?/n1#
} y-a3
catch(Exception e){e.printStackTrace ();} yH',vC.
} .vtV2lq
} j:'8yFi_
te#Wv9x
M:.0]'[s5
//打印回应的头信息 SH1)@K-
public void logResponseHead(HttpURLConnection con) 8/ PS#dM\
{ #HmZe98[%
for(int i=1;;i++) U~Rs?JmTdD
{ mW 'sdb
String header=con.getHeaderFieldKey(i); 1C<@QrT
if(header!=null) Kr@6m80E5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); '>#8 F.
Utility.log(header+" : "+con.getHeaderField(header)); /yTPb
else R2f^dt^
break; {*K7P>&
} 6[&x7"
} cPPTGpqw
}\aJ%9X02
\vqqs
public void splitterStop() P?j;&@$^e
{ ]YKxJ''u
bStop = true; . MH;u3U
} e#z#bz2<
r5'bt"K\>
t`E e/L%
} z--Y
0K^?QM|S
V ^hR%*i'
/* Jju^4
**FileAccess.java @*-t.b2k
*//文件访问(定位，写) WXe]Q bg
package NetFox; t-)d*|2n}o
import java.io.*; /G= ?E]^
"WzD+<oL
Gm-V/[29R
public class FileAccessI implements Serializable{ cSYMnB
7(C:ty9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }mOo=)C!
RandomAccessFile oSavedFile; 9i+`,r
long nPos; _[$,WuG1
,#K{+1z:
N}KL'
public FileAccessI() throws IOException |X;|=.
{ 2$FH+wuW
this("",0); 5+a5pC
} LyRW\\z2
@z>DJ>htN
2&XNT-Qm
public FileAccessI(String sName,long nPos) throws IOException 8~ u/gM
{ .:~E.b
oSavedFile = new RandomAccessFile(sName,"rw"); ry0YS\W
this.nPos = nPos; nB6 $*'
oSavedFile.seek(nPos); hRZYvZ3
} )Bu#ln"
zJo?,c
u9N/9
public synchronized int write(byte[] b,int nStart,int nLen) ~]SCf@pRk
{ k{D0&
int n = -1; G%viWWTY
try{ zZ;V9KM>v
oSavedFile.write(b,nStart,nLen); "v/Yw'! )
n = nLen; (#8B
} wU|jw(
catch(IOException e) n0g8B
{ DhXV=Qw
e.printStackTrace (); RoNE7|gF:
} +QP(ATdM
Zxh<pd25Y
P=l 7m*m
return n; <Yg6=e
} v[V7$.%5Q
[9G=x[
~BMUea(
} wHh6y?g\
oX7_v_:J\R
w)&?9?~
/* {vdY(
**SiteInfoBean.java aW9\h_$
*/ i|m8#*Hd
package NetFox; NxnaH!wS
~F%sO'4!
/B)2L]6p
public class SiteInfoBean { L7R!,
H4W!Md
uh`5:V
private String sSiteURL; //Site's URL ,&y_^-|d
private String sFilePath; //Saved File's Path _D$1CaAYo
private String sFileName; //Saved File's Name <KfR)7I$0a
private int nSplitter; //Count of Splited Downloading File +\$c_9|C+
>@Pw{Zh$
iiF`2
public SiteInfoBean() wY ??#pS
{//nSplitter的缺省值为5 ZMLN ;.{Na
//default value of nSplitter is 5 Kwi+}B!
this("","","",5); RA?_j$
} Jg)( F|>o
8!YQ9T[
:s\zk^h?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^VW]Qr!
{ vG7Mk8mIr
sSiteURL= sURL; {]dG 9
sFilePath = sPath; TQb@szp:|
sFileName = sName; -<9Qez)y
this.nSplitter = nSpiltter; P_'{|M<?
&*Xrh7K2e
3Gr"YG{,
} RN|Bk
v 2p
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public String getSSiteURL() bI|{TKKN&P
{ #Hz9@H
return sSiteURL; LT>_Y`5>
} 6212*Z_Af
@$!6u0x
?@Q0;LG
public void setSSiteURL(String value) 63J3NwFt
{ dQ~GE}[
sSiteURL = value; cJbv,RV<
} &@'%0s9g
$MGKGWx@E
B8?9L8M}
public String getSFilePath() wN10Drc
{ w=<E)
return sFilePath; Ly3!0P.<
} xf/K+
j`q>YPp
EpKZ.lCU
public void setSFilePath(String value) pdER#7Tq
{ n#Dy YVb
sFilePath = value; 'jMs&
} _>]/.w2=
maHz3:
;?@Rq"*
public String getSFileName() H! 5Ka#B
{ -^yc<%U
return sFileName; GM9[ 0+u;
} SP<Sv8Okj
\m}a%/
<}A6 )=T
public void setSFileName(String value) N\&VJc
{ v;5-1
sFileName = value; Q]GS#n
} ks("( nU
5de1rB|
=liyd74%`
public int getNSplitter() /m;Bwu
{ A^+kA)8
return nSplitter; -T1R}ew*t
} v;G/8>GRy
u/wX7s
s.rQiD
public void setNSplitter(int nCount) xzA!,75@U
{ &&52ji<3
nSplitter = nCount; h$$JXf
} R[6R)#o
} r}e(MT:R'
'YGP42#
K3h];F!^
/* {+cx}`
**Utility.java U';)]vB$
*/ ^Ss<<
package NetFox; PPrvVGP
T"3LO[j+
bv(+$YR
public class Utility { 0%,W5w
## vP(M$
v(JjvN21
public Utility() eYoc(bG(+
{ g\/|7:yB]
9}2/ko
% q!i
} .Jg<H %%f
CE
//线程睡眠 i$3#/*Y7_L
public static void sleep(int nSecond) dc~vQDNw[X
{ C"`\[F`.k
try{ _X<V`, p
Thread.sleep(nSecond); g0a!auWM
} P|?nx"c
catch(Exception e) &WAU[{4W
{ oa7 N6
e.printStackTrace (); KYKF$@ <G
} o](ORS$~
} R6>*n!*D@
ho~WD'i
//日志 @W(,|xES
public static void log(String sMsg) ~e,K
{ }V.fY3J-
System.err.println(sMsg); -~\7ZRP8
} c<cYX;O
jL4"FTcE]3
X,o ]tgg=
public static void log(int sMsg) a04S&ezj
{ p((.(fx
System.err.println(sMsg); B}p.fE
} ]>sMu]biH
} F3Vvqt*2
?W?n l:F
MfLus40;n
/* (lYC2i_b#
**TestMethod.java _Bn8i(
*/ /n,a0U/
package NetFox; QiRx2Z*\
JL:B4f%}B
Ai)Q(]
public class TestMethod { ,<OS:]
#&{)`+!"
#LwDs,J:
public TestMethod() /~<Przw
{ ///xx/weblogic60b2_win.exe <_bGV
try{ )In;nc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #]}G{ P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mUb2U&6(
SiteFileFetch fileFetch = new SiteFileFetch(bean); c1f`?i}.
fileFetch.start(); 3i}$ ~rz]U
} /h&>tYVio
catch(Exception e){e.printStackTrace ();} uA%F0oM
tE=$#
FW<YN;
} ><6g-+*k
'+S!>Lqb
,?GAFgK:
public static void main(String[] args) etP`q:6^c
{ (G"/C7q
new TestMethod(); rIH+X2x
} %o0.8qVJi
} m%OX< T!
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