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)); Q7u|^Gu,5
} #c:@oe4v
for(int i=0;i<nEndPos.length-1;i++) =H7p&DhD[
{ Y1lUO[F j
nEndPos = nStartPos[i+1]; \X %#-y
} Sck!w 3
nEndPos[nEndPos.length-1] = nFileLength; 'R1C-U3w,
} kt Z~r. +
} [DpOI
C+\z$/q
MY{Kq;FvRP
//启动子线程 A23K!a2u&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \@PMj"p|:
for(int i=0;i<nStartPos.length;i++) i$pUUK
{ X,3"4 SK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YAR$6&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ExS&fUn`C
nStartPos,nEndPos,i); P[aE3Felk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '[6]W)f
fileSplitterFetch.start(); :&5u)
} BUZ74
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [e,xC!2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \u.5_ g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >? o5AdZ
nEndPos = " + nFileLength); ;PVE= z+y
// fileSplitterFetch[nPos.length-1].start(); yVzV]&k
&H+wzx<
R[F`b
//等待子线程结束 H5]q*D2
//int count = 0; .+2:~%v6
//是否结束while循环 4grV2xtX
boolean breakWhile = false; %^W(sB$b
\aSc2Ml]3n
&7kLSb&|;
while(!bStop) bZSt<cH3
{ =?L16mu1&
write_nPos(); =WN8><K!
Utility.sleep(500); $o9^b Z
breakWhile = true; oTk\r$4eb
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for(int i=0;i<nStartPos.length;i++) Af]BR_-
{ l
if(!fileSplitterFetch.bDownOver) "/O07l1Q<
{ {uwPP2YD,
breakWhile = false; gT[]"ZT7
break; )cgNf]oy
} (|O(BxS
} Dg^s$2
if(breakWhile) + d>2'
break; k=t{o
wR 2`*.O
1_&W1o
//count++; O|m-[]
//if(count>4) IF&edP[V
// siteStop(); -= c&K&
} S]E|a@kD3
R(> oyxA[F
5 3+C;]J
System.err.println("文件下载结束！"); Hj-n 'XZ
} y[f%0*\B
catch(Exception e){e.printStackTrace ();} U&^(%W#
} @0:Eg1-
[C ezz5
U0|wC,7"
//获得文件长度 <_8eOL<X
public long getFileSize() M$v\7vBgO!
{ Ai%Wt-
int nFileLength = -1; ! .Pbbs%
try{ n%2c<@p#
URL url = new URL(siteInfoBean.getSSiteURL()); *` -
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ye^#]%m
httpConnection.setRequestProperty("User-Agent","NetFox"); Yh,,(V6
aEUEy:.
).Z U0fV
int responseCode=httpConnection.getResponseCode(); f U<<GK70
if(responseCode>=400) i @M^l`w
{ 0kp{`3ce
processErrorCode(responseCode); " u]X/ {L
return -2; //-2 represent access is error 3DjX0Dx/l
} f#38QP-T
<@>icDFEHn
gBgaVG
String sHeader; ?MRT
rJ4A9d3:
!y1qd
for(int i=1;;i++) Ux);~P`/o
{ w$qdV,s 7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u~t%GIg
//Utility.log(in.readLine()); [*vR&4mk
sHeader=httpConnection.getHeaderFieldKey(i); M&(0n?R"R
if(sHeader!=null) 7 A{R0@
{ 'cN3Vvk
if(sHeader.equals("Content-Length")) 9$sx+=(
{ [2!?pVI
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 06af{FXsGb
break; G`v(4`tA
} uMFV^&ZF
} 9j5k=IXg#a
else Y>i Qp/k:
break; 1N.weey}W
} LqQ&4I
} 6 #jpA.;
catch(IOException e){e.printStackTrace ();} cW{Bsr
catch(Exception e){e.printStackTrace ();} sVS),9\}
a{I(Qh!}
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Utility.log(nFileLength); s|Vbc@t
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aH$DEs
return nFileLength; e&pt[W}X%u
} HvG~bZN
,7Q b24A
mj& 4FQ#O*
//保存下载信息（文件指针位置） Wh?3vZ^
private void write_nPos() T ^`R
{ yEL5U{
try{ @vi;P ^1!
output = new DataOutputStream(new FileOutputStream(tmpFile)); t] G hONN
output.writeInt(nStartPos.length); bmRp)CYd
for(int i=0;i<nStartPos.length;i++) XJ1<!tl
{ Vg`32nRN
// output.writeLong(nPos); > 8!9
output.writeLong(fileSplitterFetch.nStartPos); a[BIY&/Q
output.writeLong(fileSplitterFetch.nEndPos); QlnI&o
} %vWh1-
output.close(); #"JtH"pF
} r[&/*~xL
catch(IOException e){e.printStackTrace ();} /:w.Zf>B9
catch(Exception e){e.printStackTrace ();} O=}jg0k
} C/z0/mk
h"$],=
K"=I,Vr:
//读取保存的下载信息（文件指针位置） 4V 5
private void read_nPos() -[A=\]RfJ
{ @3Mp>u/
try{ <QRRD*\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JW=P}h
int nCount = input.readInt(); oe1$;K>.7
nStartPos = new long[nCount]; \4hB1-
nEndPos = new long[nCount]; =@ed{~
for(int i=0;i<nStartPos.length;i++) $@ZrGT
{ Cbr>\;sc2Z
nStartPos = input.readLong(); '_M"yg6d
nEndPos = input.readLong(); :&=`xAX-
} k 3oR:
input.close(); ;LFs.Jc<
} 7,D6RP(b
catch(IOException e){e.printStackTrace ();} >KCnmi
catch(Exception e){e.printStackTrace ();} FJ V!B&
} pM_oIH'8:
-* piC(
.^FdO$"
private void processErrorCode(int nErrorCode) oAq<ag\qV
{ =8 Jq'-da
System.err.println("Error Code : " + nErrorCode); /HM0p
} OYk/K70l3
uU`Mq8)R
FP h1}qS
//停止文件下载 wb (quu
public void siteStop() k9oLJ<.k
{ e_t""h4D
bStop = true; af;~<oa
for(int i=0;i<nStartPos.length;i++) i{nFk',xX
fileSplitterFetch.splitterStop(); `Ct fe8
ood,k{
rTYMN
} ^yVKW5x
} 6nHyd<o
//负责部分文件的抓取 -@G,Ry-\t
**FileSplitterFetch.java `RLn)a
*/ !:<n]-U
package NetFox; Hyz:i)2
+ Awo\;@,
U=\!`_f':
import java.io.*; kmF@u@5M
import java.net.*; (GDW9:
H6%%n X
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public class FileSplitterFetch extends Thread { f-l(H="e
}*M>gvPo
x`gsD3C
String sURL; //File URL 4^AdSuV
long nStartPos; //File Snippet Start Position Qj',&b
long nEndPos; //File Snippet End Position ?LA`v_
int nThreadID; //Thread's ID jun$CY4
boolean bDownOver = false; //Downing is over 5"I8ric
boolean bStop = false; //Stop identical z!:%Hbh=
FileAccessI fileAccessI = null; //File Access interface Ny)N
rIZ^ix-N
QwgP+ M+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "1%YtV5R{
{ EnnE@BJ"
this.sURL = sURL; u40<>A
this.nStartPos = nStart; YO`V'6\
this.nEndPos = nEnd; ?'r=>'6D
nThreadID = id; |$a!Zx94^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UU"'
} d{G*1l(X
We*&\e+"T
E [b6k&A
public void run() l5esx#([*R
{ iF'qaqHWY4
while(nStartPos < nEndPos && !bStop) !1cVg ls|
{ tg'2v/
`78)|a*R.
[5sa1$n96G
try{ SK G!DKQ
URL url = new URL(sURL); %Y*]eLT>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UKBaGX:v
httpConnection.setRequestProperty("User-Agent","NetFox"); &5o ln@YL
String sProperty = "bytes="+nStartPos+"-"; LyA}Nd]pyq
httpConnection.setRequestProperty("RANGE",sProperty); N@r`+(_t
Utility.log(sProperty); Cp.qL
pLea 4
;f+bIYQz
InputStream input = httpConnection.getInputStream(); Y5?OJO{h"
//logResponseHead(httpConnection); El:&
$%BNoSK
EHqcQx`K_
byte[] b = new byte[1024]; E-J<%+
int nRead; pu?D^h9/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^4 ?LQ[t'
{ N9=1<{Z
nStartPos += fileAccessI.write(b,0,nRead); kcN#g-0
//if(nThreadID == 1) z*B-`i.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F>/"If#
} b'$fr6"O1
q7ubRak
{;| >Qn
Utility.log("Thread " + nThreadID + " is over!"); )=@SA`J
bDownOver = true; S1D=' k]
//nPos = fileAccessI.write (b,0,nRead); <9jN4hV
} 1xzOD@=dI
catch(Exception e){e.printStackTrace ();} Nr#" 5<W
} 2E*h,Mo
} }SZU'lYHoM
c6_i~0W56
|;k@Zlvc
//打印回应的头信息 oZSPdk
public void logResponseHead(HttpURLConnection con) T?Y/0znB*
{ 95%QF;h
for(int i=1;;i++) "[tb-$ER
{ &D*22R4{CX
String header=con.getHeaderFieldKey(i); ZI/Ia$O
if(header!=null) oQ"J>`',
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~|5B
Utility.log(header+" : "+con.getHeaderField(header)); -J\R}9 lIm
else qVMBZ\`Qm
break; 5 i;n:&Y
} L>.*^]
} UG:S!w'
na,i(m?l
TM2pE/P
public void splitterStop() %6eQ;Rp*
{ h1+lVAQbT
bStop = true; E[kf%\
} 0` \!O(jJ
dAkJ5\=*
6< O|,7=_
} 0JS#{EDh+
y|(C L^(
eB,eu4+-
/* q6a7o=BP]
**FileAccess.java t],5{UF
*//文件访问(定位，写) g6p:1;Evf
package NetFox; T>qI,BEY
import java.io.*; +o[-ED
`@)>5gW&p
{RPZq2Tpc
public class FileAccessI implements Serializable{ ZxvBo4>tH
Kdr7JQYzuz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ia!B8$$'RP
RandomAccessFile oSavedFile; FQW{c3%qZ
long nPos; AaX][2y8
kK&M>)&o#
ll8Zo+-[
public FileAccessI() throws IOException Tw+V$:$$
{ nXFPoR)T
this("",0); (`me}8
} xq-TT2}<L
pf[m"t6G~
S&Szc0-|k
public FileAccessI(String sName,long nPos) throws IOException Bt[Wh@
{ lJIcU RI4
oSavedFile = new RandomAccessFile(sName,"rw"); !Pf6UNN'
this.nPos = nPos; `y0u(m5
oSavedFile.seek(nPos); z8-dntkf
} NL}Q3Vv1.
}ofx?s}
L-z9n@=8\
public synchronized int write(byte[] b,int nStart,int nLen) Gw1Rp
{ N&jHU+{OU
int n = -1; w+W!dM
try{ Cyu= c1D;
oSavedFile.write(b,nStart,nLen); fv+t%,++:
n = nLen; {#C)S&o)6
} 5[5|_H+0
catch(IOException e) 0LD$"0v/C3
{ L=#nnj-
e.printStackTrace (); = iXHu *g
} wJMk%N~R:
CD:$22*]
v{c,>]@
return n; 3[;fO_R
} ScCA8JgY
G%FLt[
S\"#E:A
} ]21`x
x*7Q
" .<>(bE
/* s=[T,:Z
**SiteInfoBean.java ^sqTgrG
*/ u}QcyG^
package NetFox; U"L7G$
,:=g}i
*-\qO.4\
public class SiteInfoBean { 3$f+3/l
$rV4JROb
pr?k~Bn
private String sSiteURL; //Site's URL ;]\>jC
private String sFilePath; //Saved File's Path I3,0vnE@
private String sFileName; //Saved File's Name rm?C_
private int nSplitter; //Count of Splited Downloading File UVlh7wjg
%yPjPUHy
k;V (rf`
public SiteInfoBean() )1, U~+JFU
{//nSplitter的缺省值为5 `)WC|=w2
//default value of nSplitter is 5 M7gb3gw6
this("","","",5); *F;W 1TF
} Gr8%%]1!0
,`,1s9\&t
^{{0ajI9C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U ljWBd
{ "[ #.
sSiteURL= sURL; x +]ek
sFilePath = sPath; =Vat2'>+
sFileName = sName; /mG-g%gE
this.nSplitter = nSpiltter; u?7^+z
G<M9 6V
u8r<B4k
} B]#^&89wG)
GFTOP%Tgl
8Ao-m38
public String getSSiteURL() ;q&uk-
{ U uEm{
return sSiteURL; FFq8LM8
} SbXV'&M2AT
KD^n7+w%
@fh:lsw
public void setSSiteURL(String value) 7Q0vwKC8>
{ w`I+4&/h
sSiteURL = value; A{%LL r:
} a&Z;$
Bg.
Oj8xc!d'
public String getSFilePath() Dp-j(F
{ q#PMQR"C
return sFilePath; X4CiVV
} j.kv!;Rj=
nq qqP
!S#K6:
public void setSFilePath(String value) L};P*{q2Z
{ 3g87ir
sFilePath = value; a[=;6!
} 0iI|eE o
zK>}x=
'37 <+N
public String getSFileName() 'OI(MuSn
{ UK5u"@T
return sFileName; aNUMF
} p}p}!M|
Vl/fkd,Z
3FG'A[x3O
public void setSFileName(String value) hdDL92JVg
{ )(+q~KA}
sFileName = value; _sAcvKH
} sL],@z8<k
{RN-rF3w
sB0m^Y'
public int getNSplitter() JH._/I
{ 3}5Ya\x
return nSplitter; }CM#jN?(
} /HVxZ2bar
dlH&8
N{H#j6QW
public void setNSplitter(int nCount) Yy0U2N[i
{ t1ers> h
nSplitter = nCount; *X uIA-9
} PckAL
} NtNCt;_R7
d)kOW!5\
^B$cfs@*
/* M^{=&
**Utility.java n(#[[k9&Ic
*/ {~`{bnx^]7
package NetFox; >02p,W6S>
yp]z@SYA@
J"K(nKXO_?
public class Utility { U>0bgL
w[g`)8Ib
e)$a;6
public Utility() _wUg+Xs]
{ K0|:+s@u
Ctbc!<@o
:A+}fBIN
} "a-;?S&
#giH`|#d
//线程睡眠 pP%9MSCi
public static void sleep(int nSecond) 7c83g2|%
{ F_@?'#m
try{ vi]cl=S
Thread.sleep(nSecond); 63QF1*gPH
} Q@[(0R1
catch(Exception e) U~w8yMxX
{ O-ppR7edh
e.printStackTrace (); oG\lejO
} <B!DwMk;.
} NH4T*R)Vz
1[!7xA0j
//日志 :OV6R,
public static void log(String sMsg) [Pl''[
{ B & ]GGy
System.err.println(sMsg); n7.85p@ua
} f^lhdZ\
q+ `QiPj
qWS"I+o,S
public static void log(int sMsg) : . PRM+
{ [WI'oy
System.err.println(sMsg); Bh7hF?c Sj
} ccT <UIpq
} wli H3vA_
/4;Sxx-
ji<(}d~L*
/* :mhO/Bx
**TestMethod.java N]-skz<v
*/ >z73uKA(
package NetFox; R&Ss ET.
,[<$X{9
thz[h5C?C
public class TestMethod { m#<Jr:-
Kw(S<~9-@
e/x6{~ju^N
public TestMethod() @sUec
{ ///xx/weblogic60b2_win.exe v6ei47-
try{ n<1*cL:8B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Rm`P.;%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TW}].A_-
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^fE8|/]nG9
fileFetch.start(); IY|`$sHb
} `VF_rC[?
catch(Exception e){e.printStackTrace ();} yb,$UT"]
WM7LCP
Tj}%G
} [=cYsW%WG
Awr(}){
@"H7Q1Hg!*
public static void main(String[] args) g_rk_4]
{ (\nEU! Y
new TestMethod(); OIkjO}/7
} K"ly\$F
} @>&b&uj7T
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