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)); (S|a 9#
} QdDObqVdy
for(int i=0;i<nEndPos.length-1;i++) 9~c~E/4!
{ 1AF%-<`?s
nEndPos = nStartPos[i+1]; >SoO4i8
} /v|Onq1Y4
nEndPos[nEndPos.length-1] = nFileLength; D+sQPymI
} Lz@$3(2
} :&qhJtGo
k#C f})
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//启动子线程 2ev*CX6.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @4drjT
for(int i=0;i<nStartPos.length;i++) 1a$IrQE
{ :=<0=JE#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }_}KVI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TQf L%JT
nStartPos,nEndPos,i); BC! 6O/kr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U]hF
fileSplitterFetch.start(); hv>KX
} ZjD)?4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '^iUx,,ZQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v^SsoX>WMH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q8>t!rh<R
nEndPos = " + nFileLength); @TzvT3\q
// fileSplitterFetch[nPos.length-1].start(); #6=MKpR
(wuaxo:
*0y{ ~@
//等待子线程结束 byGn,m
//int count = 0; qsI^oBD"
//是否结束while循环 QXVC\@
boolean breakWhile = false; j13DJ.xu
R>2IRvY(
I{ ryD -!
while(!bStop) 6Ps.E
{ ?59'dGnz_
write_nPos(); &gn-Wb?
Utility.sleep(500); "uKFOV?j&
breakWhile = true; Fi2xr<7"
sN~\+_
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for(int i=0;i<nStartPos.length;i++) +C+<BzR~A.
{ $6h*lT<
if(!fileSplitterFetch.bDownOver) J;}3t!
{ XF*.Jg]
breakWhile = false; M;jcUX_{
break; }D*yr3b
} T\9~<"P^
} :,S98z#
if(breakWhile) z.oU4c
break; gL3iw!7
Pbn!KX~F~
\X|sU:g
//count++; yNCEz/4
//if(count>4) Eectxyr?;N
// siteStop(); h3!$r~T!a:
} PFrfd_s{>\
#%$28sxB
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System.err.println("文件下载结束！"); };,/0Fu
} 8'#/LA[uPe
catch(Exception e){e.printStackTrace ();} jlqv2V7=/
} .cDOl_z<:G
g/~XCC^F?
W)*p2#l
//获得文件长度 O o8qyW
public long getFileSize() +=BAslk
{ ;65D
int nFileLength = -1; y(W|eBe
try{ ZU{4lhe
URL url = new URL(siteInfoBean.getSSiteURL()); z6*<V5<7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 1V^L}
httpConnection.setRequestProperty("User-Agent","NetFox"); iW%8/$
R=]d%L8
xQ4%e[/
int responseCode=httpConnection.getResponseCode(); Kibr ]w
if(responseCode>=400) Hfym30
{ N&,]^>^u
processErrorCode(responseCode); o!c] (
return -2; //-2 represent access is error ?K_ '@
} +B}0=Ex$t
][&9]omB
YA:nOvd@O
String sHeader; !bnyJA
BU|#e5
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for(int i=1;;i++) 9?<{_'
{ aUU7{o_Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3g~'5Ao
//Utility.log(in.readLine()); _S}A=hK'
sHeader=httpConnection.getHeaderFieldKey(i); `aC){&AP(
if(sHeader!=null) . pzC5Ah
{ #,d I$gY
if(sHeader.equals("Content-Length")) c;2#,m^
{ YW/QC'_iC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pe;Y1Qq>>
break; 3qL>-%):*
} vy9 w$ls
} jszK7$]^
else [ic870_
break; O@V%Cu
} f+_h !j
} Z?5V4F:f
catch(IOException e){e.printStackTrace ();} J aTp}#
catch(Exception e){e.printStackTrace ();} 457\&
kF"@Ngv.
n+;6=1d7ZW
Utility.log(nFileLength); T .FI'wy
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return nFileLength; 1KM`i
} 9h4({EE2t
aJ") <_+
~`M\Ir
//保存下载信息（文件指针位置） 0'YG6(h
private void write_nPos() ~\LCvcY"X
{ ).^}AFta
try{ ?iI4x%y
output = new DataOutputStream(new FileOutputStream(tmpFile)); eqw0]U\pv
output.writeInt(nStartPos.length); .Z:zZ_Ev
for(int i=0;i<nStartPos.length;i++) ^T"vX
{ VXLT^iX
// output.writeLong(nPos); {(U %i\F\
output.writeLong(fileSplitterFetch.nStartPos); {!t7[Ctb
output.writeLong(fileSplitterFetch.nEndPos); ,I1RV
} 0j"8@<
output.close(); npJt3 Y_I
} D=m'pL/pl
catch(IOException e){e.printStackTrace ();} #P l~R
catch(Exception e){e.printStackTrace ();} Ms~{9?
} 8_<4-<}P:
+LM#n#T
bef_rH@`
//读取保存的下载信息（文件指针位置） OyU
private void read_nPos() _8Kx6s%
{ NS%WeAf
try{ {M-YHX>*;g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?HF%(>M
int nCount = input.readInt(); S}p4iE"n
nStartPos = new long[nCount]; s<qe,'Y
nEndPos = new long[nCount]; P9g en6
for(int i=0;i<nStartPos.length;i++) V=:'SL*3|
{ \7Jg7*
nStartPos = input.readLong(); z9FfU
nEndPos = input.readLong(); g35DV6
} Tq]Sn]CSP
input.close(); 1$M@]7e+!+
} 79`AM X[b
catch(IOException e){e.printStackTrace ();} \b%kf99
catch(Exception e){e.printStackTrace ();} ^6_e=jIN
} +s- lCz
h4q|lA6!k8
CC#;c1t
private void processErrorCode(int nErrorCode) d ,4]VE
{ ~HOy:1QhE=
System.err.println("Error Code : " + nErrorCode); oE#d,Z
} GrUCZ<S
`c<;DhNO
_%5Ro6
//停止文件下载 ='`/BY(m[
public void siteStop() O8B\{T1
{ &f^,la
bStop = true; S30?VG9U0f
for(int i=0;i<nStartPos.length;i++) kS bu]AB
fileSplitterFetch.splitterStop(); emCM\|NQg&
+=O5YR!{
7;KwLT9
} zIh['^3.n
} T6 '`l?H`;
//负责部分文件的抓取 bbrXgQ`s+w
**FileSplitterFetch.java c-B cA
*/ vI>>\.ED
package NetFox; .zi_[
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E[/\7v\
import java.io.*; SQX:7YF~
import java.net.*; RhncBKm*M
Ney/[3 A
8C*c{(4
public class FileSplitterFetch extends Thread { SHe49!RA'{
z^'gx@YD*v
S:h{2{
String sURL; //File URL ~`aa5;Ab_
long nStartPos; //File Snippet Start Position |Y?HA&
long nEndPos; //File Snippet End Position zd@m~V
int nThreadID; //Thread's ID 7Zlw^'q$:L
boolean bDownOver = false; //Downing is over M7pOLP_1jB
boolean bStop = false; //Stop identical WA+iYLx@H
FileAccessI fileAccessI = null; //File Access interface u6AA4(
`$ 6rz
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vN`klDJgW[
{ ibj87K
this.sURL = sURL; vX/T3WV
this.nStartPos = nStart; C uB`CI
this.nEndPos = nEnd; !@}wDt
nThreadID = id; I}1NB3>^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wOU_*uY@6'
} kM,C3x{A
C{U?0!^
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public void run() H{Wu]C<@p
{ A~)D[CV
while(nStartPos < nEndPos && !bStop) &litXIvT>
{ y*qVc E
As'=tIro
YNQY4\(
try{ <0Xf9a8>
URL url = new URL(sURL); \W~N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =vX/{C
httpConnection.setRequestProperty("User-Agent","NetFox"); sB7# ~pA
String sProperty = "bytes="+nStartPos+"-"; Zy`m!]G]80
httpConnection.setRequestProperty("RANGE",sProperty); h1de[q)
Utility.log(sProperty); 16=sij%A
Sc;BCl{=|
4K\G16'$v
InputStream input = httpConnection.getInputStream(); 8Vr%n2M
//logResponseHead(httpConnection); [_k1jHr48N
pH9VTM.*
\NPmym_6J
byte[] b = new byte[1024]; .P8&5i)'P,
int nRead; fp`;U_-&0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;ub;lh3
{ +S o4rA*9
nStartPos += fileAccessI.write(b,0,nRead); X $jWo@
//if(nThreadID == 1) ZOh`(})hy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b,7k)ND1F
} EJMM9(DQ7
=;Au<|
B38]~'8
Utility.log("Thread " + nThreadID + " is over!"); l9{hq/V
bDownOver = true; GeH#I5y
//nPos = fileAccessI.write (b,0,nRead); z&zP)>Pv
} 8\+uec]k
catch(Exception e){e.printStackTrace ();} H\ F:95
} KcWN,!G
} m|n
5?{r
+^60T$
//打印回应的头信息 TM%|'^)
public void logResponseHead(HttpURLConnection con) ]cHgleHQ
{ >g1~CEMN#
for(int i=1;;i++) 9X}10u:
{ ]_f_w9]
String header=con.getHeaderFieldKey(i); marQNZ
if(header!=null) hOjk3 k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j#!IuH\]
Utility.log(header+" : "+con.getHeaderField(header)); cr7 }^s
else gb[5&>(#
break; M?1Y,5
} =^M/{51j
} L/$H"YOv
Ag-(5:
8\&X2[oAD
public void splitterStop() XO.jl"xu
{ slCx w$
bStop = true; }Y12
} n(1l}TJy
-*1d!
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} ?gA 8x
)|ju~qbf
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/* L+b6!2O,
**FileAccess.java X_q\Sg
*//文件访问(定位，写) q+yQwX{
package NetFox; f\|w'
import java.io.*; n@<YI
V'z1
9}rS(/@ }
public class FileAccessI implements Serializable{ 5TH~.^`Fi
ejSji-Qd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZF!h<h&,
RandomAccessFile oSavedFile; (nQ^
long nPos; p$S*dr
NVkV7y X]
`KZm0d{H
public FileAccessI() throws IOException 5'OrHk;u
{ 3#LlDC_WC
this("",0); 8I=2lK
} =9H7N]*h
Vr3Zu{&2
KjD/o?JUr
public FileAccessI(String sName,long nPos) throws IOException {&&z-^
{ ?g_3 [Fk
oSavedFile = new RandomAccessFile(sName,"rw"); )8a~L8oN
this.nPos = nPos; =Qy<GeY
oSavedFile.seek(nPos); \j$&DCv
} G<L;4nA)
yuh *
ik)|{%!K]H
public synchronized int write(byte[] b,int nStart,int nLen) X]ipI$'+C
{ ?qb}?&1
int n = -1; 2=*H 8'k
try{ OAgniLv
oSavedFile.write(b,nStart,nLen); 9SX +
n = nLen; AP3a;4Z#
} k R?qb6
catch(IOException e) y6g&Y.:o
{ >xN .F/[K
e.printStackTrace (); M[NV)q/)
} j * %
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&h}#HS>l
return n; \;,_S+Fz8
} _P!m%34|
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xVw9v6@`h
} 2R[:]-b
aS>u,=C
K%t*8 4j
/* Kew@&j~
**SiteInfoBean.java y\/1/WjBn
*/ ))qy;Q,
package NetFox; x`mG<Yt
oh4E7yN
vx{}}/B]J
public class SiteInfoBean { })'B<vq
,V7nzhA2
M`0V~P`^
private String sSiteURL; //Site's URL S;Fi?M
private String sFilePath; //Saved File's Path {B~QQMEow
private String sFileName; //Saved File's Name 9=s<Ld
private int nSplitter; //Count of Splited Downloading File ko!)s
kXViWOXU^
W~)}xy
public SiteInfoBean() 21n?=[
{//nSplitter的缺省值为5 v_yw@
//default value of nSplitter is 5 t$`r4Lb9/
this("","","",5); &j;wCvE4+
} ___~D dq
Mc)}\{J
aEB_#1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <;lkUU(WT2
{ [|v][Hwv
sSiteURL= sURL; \P[Y`LYL
sFilePath = sPath; kBS9tKBWg
sFileName = sName; q9B$"n
this.nSplitter = nSpiltter; }H53~@WP>
Lw1Yvtn
!n`fTK<$
} &<z1k-&!
8C40%q..
BT !^~S%w
public String getSSiteURL() YqscZ(L:y
{ e+EQ]<M
return sSiteURL; 5=-Q4d
} @@f"%2ZR[
yWmJ~/*lG
8|gIhpO?^
public void setSSiteURL(String value) Q3'llOx
{ 6bg ;q(*7
sSiteURL = value; ~g91Pr
} aj='b.2)
}{Pp]*I<A
yxPazz
public String getSFilePath() p T?}Kc
{ 3Tcms/n
return sFilePath; X0HZH?V+
} \ #F
hgG9m[?K
ic:zsuEm
public void setSFilePath(String value) '@v\{ l
{ #~]zhHI
sFilePath = value; @mCEHI{P
} |"}FXaO
yX>K/68
u,ho7ht3(
public String getSFileName() WCZjXDiwJ
{ :U|1xgB
return sFileName; B`)BZ,#p
} e+7"/icK
(TtkFo'!U
NWESP U):w
public void setSFileName(String value) /8'NG6"H`
{ K8|r&`X0
sFileName = value; q>_.[+6
} I9A~Ye 5O&
P8:dU(nlW
$S6`}3
public int getNSplitter() b#%hY{$j
{ 7~h<$8Y(T
return nSplitter; C^Yb\N}S
} -m zIT4
u{cW:
P= BZ+6DS
public void setNSplitter(int nCount) ?>:g?.+
{ QE+g j8
nSplitter = nCount; /KaZHR.
} b~P`qj[
} \!X8
VBlYvZ;$*
t.y2ff<[U
/* H7Rx>h_
**Utility.java ?=msH=N<l
*/ /U*C\ xMm
package NetFox; J1U/.`Oy
`g?Negt\v
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public class Utility { xj)F55e?
HyQJXw?A:
(S5R!lpO
public Utility() u@)U"FZ
{ a5"D@E
C==hox7b
M<Ncb
} QVT5}OzMt
@i_FTN
//线程睡眠 ?zMHP#i
public static void sleep(int nSecond) <NY^M!
{ `$IK`O
try{ fplow
Thread.sleep(nSecond); ys^oG$lq
} Lg+Ac5y}`
catch(Exception e) +)om^e@.
{ H|<[YYk
e.printStackTrace (); eKgBy8tNS0
} ?!:ha;n
} \:'/'^=#|
DPxM'7
//日志 B]wk+8SMY.
public static void log(String sMsg) H2\;%K 2
{ .VJMz4$]O
System.err.println(sMsg); CsR$c,8X.
} 1=c\Rr9]
&{hL&BLr
L#{S!P,"
public static void log(int sMsg) re?,Wext\
{ M)+H{5bt
System.err.println(sMsg); /Iy]DU8
} SM#]H-3
} !Pvf;rNI1T
VcYrK4
ek\ xx
/* rU:`*b<
**TestMethod.java /t57!&
*/ R?|.pq/Ln
package NetFox; /SR*W5#s
#Y`~(K47
[({nj`
public class TestMethod { %N6A+5H
2#]#sZmk
~$cV:O7
public TestMethod() \ZFGw&yN
{ ///xx/weblogic60b2_win.exe KP^V>9q
try{ `2WFk8) F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )[6U^j4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZY={8T@
SiteFileFetch fileFetch = new SiteFileFetch(bean); <?6|.\&
fileFetch.start(); #U4F0BdA
} Gr' CtO
catch(Exception e){e.printStackTrace ();} bHYy}weZ
34O `@j0-3
nwe*BVp
} 85$m[+md
dr}`H,X"3
6r0krbN
public static void main(String[] args) |bHelD|
{ -UEZ#Q
new TestMethod(); TDKki(o=~
} BLdvyVFx
} ]i)c{y
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