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)); [TV"mA
} 8<^6<c
for(int i=0;i<nEndPos.length-1;i++) ^_ZQf
{ :kI x?cc
nEndPos = nStartPos[i+1]; .uagD[${
} }Lwj~{
nEndPos[nEndPos.length-1] = nFileLength; **YNR:#Y
} 48%a${Nvvj
} Ah2XwFg?
T{K+1SPy4
o:Z*F0qm
//启动子线程 +FVcrL@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l:+pO{7L
for(int i=0;i<nStartPos.length;i++) <Q-ufF85)
{ Mz{ Rh+gS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !"J*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tbv6-)Hs
nStartPos,nEndPos,i); g?o$:>c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /[#{#:lo2
fileSplitterFetch.start(); L@R%*-a
} I0jEhg%JZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Iei4yDv ;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LRd,7P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XWy iS\
nEndPos = " + nFileLength); v:T` D
// fileSplitterFetch[nPos.length-1].start(); 8UL:C?eY
.}y Lz
#WpO9[b>
//等待子线程结束 A8eli=W
//int count = 0; t@19a6:Co
//是否结束while循环 nt[0krG
boolean breakWhile = false; .r*b+rc;]
U ._1'pW
s9GPDfZ
while(!bStop) TAC\2*bWje
{ @%cJjZ5y
write_nPos(); "RX?"pB
Utility.sleep(500); {}^ELw
breakWhile = true; LA@}{hU
x}>tX
hJ4.:
for(int i=0;i<nStartPos.length;i++) <,hBoHZSL
{ ze\~-0ks+
if(!fileSplitterFetch.bDownOver) IKr7"`
{ !<6wrOMaO
breakWhile = false; z=Vvb
break; FW.dHvNX
} 22r01qH
} O}f(h5!k
if(breakWhile) a!^wc,
break; A07P$3>/W
G =4y!y
B# H
//count++; w+$gY?%
//if(count>4) q(p0#Mk,E
// siteStop(); |uZ=S]V@
} tr/dd&(Y1
J+|ohA
q@-qA]
System.err.println("文件下载结束！"); @>:07]Dxo
} QF;<%QF:
catch(Exception e){e.printStackTrace ();} NU(/Yit
} h{xERIV1u
?-84_i
XP^6*}H.*
//获得文件长度 yK7>^p}V
public long getFileSize() E6@;e-]j
{ 2M#CJ&
int nFileLength = -1; )|a9Z~#x
try{ +r!h*4
URL url = new URL(siteInfoBean.getSSiteURL()); bv4cw#5z$9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $B?7u@>,
httpConnection.setRequestProperty("User-Agent","NetFox"); r=Q5=(hn
C|J1x4sb@
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int responseCode=httpConnection.getResponseCode(); .>'Z9.Xnk
if(responseCode>=400) yrs3`/
{ G0Eq}MyF
processErrorCode(responseCode); /_a *C.a6
return -2; //-2 represent access is error ;MJ1Q
} FOA%(5$4
5l}h8So4
dR+$7N$
String sHeader; R,bcE4WR"
Q8q_w2s,
[E~TYk;
for(int i=1;;i++) 7dJaWD:&
{ Xt84Evo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ):@%xoF5
//Utility.log(in.readLine()); (Qm;]?/
sHeader=httpConnection.getHeaderFieldKey(i); /6c10}f
if(sHeader!=null) 3Q}Y?rkJ5
{ %p60pn[(
if(sHeader.equals("Content-Length")) pb Ie)nK
{ 2AW{qwk7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (d#Z-w-
break; ZRm\d3x4
} w0Y%}7
} [;AcV73
else UYOn p7R<
break; 2oG|l!C
} hob$eWgr
} @EZONKT
catch(IOException e){e.printStackTrace ();} ^b %8_?2m
catch(Exception e){e.printStackTrace ();} W@dY:N}
]:fCyIE
,P@-DDJ
Utility.log(nFileLength); 30E v"
HjS^ nYl
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return nFileLength; ug"<\"
} SqF.DB~
W? ||9
m@u`$rOh
//保存下载信息（文件指针位置） UiZp-Y%ki
private void write_nPos() arKmc@"X
{ y?#J`o- O
try{ _lv:"/3R
output = new DataOutputStream(new FileOutputStream(tmpFile)); yKEFne8^
output.writeInt(nStartPos.length); DF|s,J`98
for(int i=0;i<nStartPos.length;i++) L_K\i?
{ S!W/K!wf
// output.writeLong(nPos); /.YAFH|i)"
output.writeLong(fileSplitterFetch.nStartPos); ]=VS~azZ5
output.writeLong(fileSplitterFetch.nEndPos); ?lN8~Ze
} kseJm+Hc
output.close(); S} Cp&}G{P
} 2U`W[
catch(IOException e){e.printStackTrace ();} 9XqAjez\
catch(Exception e){e.printStackTrace ();} 0(/D|
} etMh=/NFV
Guw|00w,Q$
bH&)rn
//读取保存的下载信息（文件指针位置） EQ63VF
private void read_nPos() cgxFEv
{ (2bZ]
try{ f H|QAMfOu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~gWd63%8x
int nCount = input.readInt(); L\wpS1L(
nStartPos = new long[nCount]; h`h>H X
nEndPos = new long[nCount]; :@%-f:iDj
for(int i=0;i<nStartPos.length;i++) oA;Ty7s
{ I,4-
nStartPos = input.readLong(); j-`X_8W
nEndPos = input.readLong(); ,' rL'Ys
} b}Hl$V(uD
input.close(); -N7L#a
} v<3o[mq
catch(IOException e){e.printStackTrace ();} ;[KriW
catch(Exception e){e.printStackTrace ();} ]ZKt1@4AY
} n~)HfY
}{wTlR.]
"4ozlWx
private void processErrorCode(int nErrorCode) 2iPmCG
{ 0YpiHoM
System.err.println("Error Code : " + nErrorCode); S`@6c$y k
} IFrb}yH
3_\{[_W
Vvyrty
//停止文件下载 1KYbL8c
public void siteStop() ?l, X!o6
{ )0U3w#,JQ
bStop = true; }>;ht5/i/
for(int i=0;i<nStartPos.length;i++) ?#*
fileSplitterFetch.splitterStop(); HLSfoQ&)v
3cCK"kr
9jMC|oE
} B]|6`UfB
} 2&gd"Ak(
//负责部分文件的抓取 j(%gMVu
**FileSplitterFetch.java Cv>yAt.3
*/ XatA8(_,5
package NetFox; ke}Y2sB
h eE'S/
3"'# |6O9
import java.io.*; fwi};)K
import java.net.*; Ns.3s7&
[arTx^
){+[$@9
public class FileSplitterFetch extends Thread { a1g6}ym\
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&\1'1`N1
String sURL; //File URL kRN|TDx(
long nStartPos; //File Snippet Start Position R%b*EBZ
long nEndPos; //File Snippet End Position ).NcLJw_
int nThreadID; //Thread's ID 8ji^d1G,
boolean bDownOver = false; //Downing is over w.J%qWJq
boolean bStop = false; //Stop identical Xr?>uqY!M
FileAccessI fileAccessI = null; //File Access interface Qj 6gg
cxXbo a
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1z~k1usRK
{ }rzdm9
this.sURL = sURL; Kajkw>z
this.nStartPos = nStart; ~@T+mHny
this.nEndPos = nEnd; 5-8]N>/b!
nThreadID = id; ^uyNv-'F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6P;o 6s
} brg":V1a
eM?rc55|
n$.1Wk"
public void run() 5%<TF.;-J
{ \f(Y:}9
while(nStartPos < nEndPos && !bStop) |x &Z~y
{ uu}a:qrY
|EF>Y9
O6yP qG*j
try{ )K{o<m~WAo
URL url = new URL(sURL); 2Sge
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IWAj Mwo
httpConnection.setRequestProperty("User-Agent","NetFox"); DVObrL)znL
String sProperty = "bytes="+nStartPos+"-"; q}>M& *
httpConnection.setRequestProperty("RANGE",sProperty); "@.Z#d|Y
Utility.log(sProperty); c}\ 'x5:o
d,)}+G
fO*)LPen.z
InputStream input = httpConnection.getInputStream(); B ,V(LTE
//logResponseHead(httpConnection); qh%i5Mu
gf+o1\5t@
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byte[] b = new byte[1024]; :I2H&,JT
int nRead; $zdd=.!KiK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 49o\^<4b
{ Iq+2mQi*/k
nStartPos += fileAccessI.write(b,0,nRead); F y b[{"
//if(nThreadID == 1) M9gOoYf,~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9*' &5F=
} Truc[A.2Z
W:WQaF`2x
Tj=gRQ2v
Utility.log("Thread " + nThreadID + " is over!"); JlUb0{8PE
bDownOver = true; Qe_+r(3)k
//nPos = fileAccessI.write (b,0,nRead); WhH!U0
} ThtMRB)9
catch(Exception e){e.printStackTrace ();} gt'*B5F(
} iecWa:('
} 22z1g(;@
G%;kGi`m
Y.7}
//打印回应的头信息 Hoj8okP
public void logResponseHead(HttpURLConnection con) 975 _d_U
{ avg4K*vv
for(int i=1;;i++) )#a7'Ba
{ R }1W
String header=con.getHeaderFieldKey(i); NddO*`8+)
if(header!=null) *#zS^b n
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RB[/q:
Utility.log(header+" : "+con.getHeaderField(header)); u\f3qc,]F
else SnW7x
break; f~q4{
} z?4=h Sy
} "CBRPp
b:1 L@8s;
+Juh:1H
public void splitterStop() <6/= y1QC)
{ grspt}
bStop = true; eQ;Q4
} \%TyrY+`K
z6I%wh
Z5$fE7ba+
} nM8[
!>3LGu,
>g]ON9CGH
/* w^Ag]HZN
**FileAccess.java O[FZq47
*//文件访问(定位，写) V&%C\ns4
package NetFox; dw9Tf^V
import java.io.*; 5$%XvM
m*dNrG
[1SMg$@<
public class FileAccessI implements Serializable{ 9 I{/zKq
35_)3R)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8vSIf+
RandomAccessFile oSavedFile; aClA{
long nPos; moZm0`WR
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public FileAccessI() throws IOException T<yb#ak
{ %j5ywr:
this("",0); Z!_n_Fk
} :$%>4+l
2+Yb 7 uI,
t7*#[x)a
public FileAccessI(String sName,long nPos) throws IOException ]C!?HQ{bsf
{ ]iVLHVqz
oSavedFile = new RandomAccessFile(sName,"rw"); pO]8 dE0
this.nPos = nPos; J# EP%
oSavedFile.seek(nPos); rt}^4IqL
} (>7>3
UQPU"F7.
:kG)sw7
public synchronized int write(byte[] b,int nStart,int nLen) ue\t,*KYd
{ !0"nx{7.
int n = -1; =J/FJb
try{ >2lwWXA
oSavedFile.write(b,nStart,nLen); VteEDL/w
n = nLen; >cgpajx*
} b1-&v|L
catch(IOException e) GLUUY0
{ 3CZS)
e.printStackTrace (); ,;jGJr
} *C2R`gpBI
L0"~[zB]N
G%{0i20_
return n; N+g@8Q2s;5
} :L:&t,X
PJ\0JR7a
<]d LX}C)
} ]?K. S6
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L:R<e#kgS
/* ^3~e/PKM
**SiteInfoBean.java | C+o;
*/ FHg0E++?
package NetFox; Nneo{j
5?u}#zO
:dnJY%/q
public class SiteInfoBean { 'i|rjW(
Qa4MZj;$K
+%0z`E\?M#
private String sSiteURL; //Site's URL qJv[MBjk3B
private String sFilePath; //Saved File's Path 8%:]W^
private String sFileName; //Saved File's Name 'Jj=RAV`
private int nSplitter; //Count of Splited Downloading File X#p Wyo~
A9:NKY{z
P'$ `'J]j
public SiteInfoBean() i$^ZTb^
{//nSplitter的缺省值为5 n/Dp"4H%q
//default value of nSplitter is 5 !0}\&<8/m
this("","","",5); /X*oS&-M
} sen=0SB/
A\sI<WrH
4P8*k[.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Jjm|9|C,
{ K[?Xm"4
sSiteURL= sURL; n1v5Q2xw
sFilePath = sPath; N{Qxq>6 G
sFileName = sName; ,xsH|xW
this.nSplitter = nSpiltter; nE W31 8
sRhKlUJG
9Kv|>#zff
} >Aq:K^D/3F
n.}T1q|l
+[-i%b3q
public String getSSiteURL() ROb\Rxm
{ #f,y&\Xmf
return sSiteURL; \2v"YVWw
} nv/[I,nw
7/IlL
3iNkoBCg
public void setSSiteURL(String value) $lwz-^1t.
{ )%Iv[TB[
sSiteURL = value; YwDt.6(+,
} ^QXbJJ
A#y@`}]!'
r,(Mu
public String getSFilePath() 8p^B hd
{ H`QQG!
return sFilePath; D-p.kA3MJ
} 5Rv+zQ#GR
N"7]R[*
t0E51Ic@
public void setSFilePath(String value) 0\QR!*'$
{ nms8@[4-
sFilePath = value; QG gF|c7
} A;X=bj _&a
45 >XKr.%
chI.{Rj
public String getSFileName() PL=^}{r
{ @C8DZ5)
return sFileName; HLK@xKD<
} _8?o'<!8?^
=r. >N\
/F/;G*n
public void setSFileName(String value) S~OhtHwK
{ %yS3&Ju
sFileName = value; 3251Vq %
} 1R%1h9I4'
ro~+j}*
y'C-[nk
public int getNSplitter() Tny>D0Z#
{ Z}6^ve
return nSplitter; =6nD sibf
} 5jcte< 5I_
S=|@L<O
Q /x8 #X
public void setNSplitter(int nCount) ~aK?cP
{ qt e>r
nSplitter = nCount; pW\'ZRj
} )X+mV
} [5d2D,)
qCQ./"8
15\Ph[6g
/* ! NV#U
**Utility.java *?p|F&J
*/ z_|oCT!6
package NetFox; 5z$,6T
kLSrj\6I[
?)4?V\$
public class Utility { y(jg#7)
^ZRYRA
cQNsL
public Utility() ]2SI!Ai7
{ I27,mS+]
F=a+z/xKT
&dB-r&4;+
} %q3$|>
m:QG}{<.h
//线程睡眠 B^ 7eoW
public static void sleep(int nSecond) r),PtI0X
{ sN=6gCau
try{ >p\e0n
Thread.sleep(nSecond); )(M7lq.e7
} &]6)LFm
catch(Exception e) =qVP] 9
{ ~#K@ADYr
e.printStackTrace (); gk0.zz([
} tA.`k;LT
} L71!J0@a#
nSx8E7 |V
//日志 (t^n'V
public static void log(String sMsg) ~EiH-z4U
{ n||A" @b\
System.err.println(sMsg); ?i\;:<e4
} uYI@9U
y^>Q/H\
,~PYt*X4
public static void log(int sMsg) 4<,|*hAT
{ Tb;d.^
System.err.println(sMsg); >pyj]y^3
} n 1b(\PA
} Z3KO90O!8
='?:z2lJ
q6#<[ 4?
/* R6;Phdh<>
**TestMethod.java zk_Eb?mhwV
*/ :Sg&0Wj+#j
package NetFox; .>g1$rj
,$*IzL~
)EM7,xMz
public class TestMethod { +!t}
}CL"S_>1
&jA\hg#9
public TestMethod() *hhmTc#
{ ///xx/weblogic60b2_win.exe /hWd/H]
try{ !\ND(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V)M1YZV{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C2U~=q>>
SiteFileFetch fileFetch = new SiteFileFetch(bean); rt-\g1x
fileFetch.start(); &$FvWFRh#
} nv0@xnbz
catch(Exception e){e.printStackTrace ();} q(o/yx{bm
5FKBv e@
YB))S!;Ok
} ^WYQ]@rh3
QWnndI_4p
R@Y=o].2
public static void main(String[] args) MZv]s
{ UM%o\BiO
new TestMethod(); FjfN3#qlg
} 9W7#u}Z
} j|fd-<ng
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