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)); .)=*Yr M
} <B>hvuCoH
for(int i=0;i<nEndPos.length-1;i++) pU'${Z~b
{ M?DZShkV_
nEndPos = nStartPos[i+1]; EV-sEl8ki
} _>BYUPY
nEndPos[nEndPos.length-1] = nFileLength; bDudETl
} v(GnG
} QO0@Ax\b
||fw!8E
yYSmmgrX0
//启动子线程 Ghc U~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %?, 7!|Ls
for(int i=0;i<nStartPos.length;i++) ZjY,k
{ ^$}O?y7O
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k`&FyN^)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }V*?~.R
nStartPos,nEndPos,i); `Tf}h8*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ` &bF@$((
fileSplitterFetch.start(); kvuRT`/
} 6212*Z_Af
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'n>44_7L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %hN(79:g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,i|K} Y&
nEndPos = " + nFileLength); ^/$dSXKF
// fileSplitterFetch[nPos.length-1].start(); Y652&{>q
ITg:OOQ
,A $IFE
//等待子线程结束 (F 9P1Iq
//int count = 0; v#d(Kj
//是否结束while循环 ~JNE]mg
boolean breakWhile = false; MgJ5FRQ
Ook\CK*nKe
CM$&XJzva
while(!bStop) rk4KAX_[
{ ;Z`a[\i':
write_nPos(); jMCd`Q]K
Utility.sleep(500); _'17C/
breakWhile = true; lZ)6d-vK
xf/K+
.AOc$Nt
for(int i=0;i<nStartPos.length;i++) s,f2[6\Y
{ ms;zC/
if(!fileSplitterFetch.bDownOver) ]kx<aQ^
{ ']fyD3N
breakWhile = false; S.Kcb=;"L
break; j,;f#+O`g
} SXYwhID=
} )/JVp>
if(breakWhile) 8t=O=l\
break; maHz3:
wr:W}Z@pL
H ?9Bo!
//count++; ("ix!\1K@
//if(count>4) yUD@oOVC0
// siteStop(); YgjW%q
} |bSAn*6b
{D^ )%{
ULu@"
System.err.println("文件下载结束！"); k{lo'
} w'A*EWO
catch(Exception e){e.printStackTrace ();} V6](_w!
} :RukW.MR
lK7:qo
pfIK9>i
//获得文件长度 xzOvc<u
public long getFileSize() A'7Y{oPHX
{ $H.U ~
int nFileLength = -1; WRkuPj2
try{ W( sit;O
URL url = new URL(siteInfoBean.getSSiteURL()); :h(3Ep
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BTj1C
httpConnection.setRequestProperty("User-Agent","NetFox"); N0}[&rE 8
;<[!;8
/DH`7E
int responseCode=httpConnection.getResponseCode(); OmZZTeGg1s
if(responseCode>=400) "PElQBLP:
{ 0sKoNzE
processErrorCode(responseCode); [ ^\{>m7
return -2; //-2 represent access is error dc4XX5Z
} aM1WC 'c&)
COm^ti-p
3!@&7@p
String sHeader; #y7MB6-
rA8NE>
-c1-vGW/
for(int i=1;;i++) qGR1$\]
{ ujE~#b}X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sx;/xIU|
//Utility.log(in.readLine()); |oSt%lQ1
sHeader=httpConnection.getHeaderFieldKey(i); A{B$$7%
if(sHeader!=null) `L <sZ;Cj
{ .t>SbGC
if(sHeader.equals("Content-Length")) S1)g\Lv
{ MIl\Bn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]j,o!|rx7
break; NX(IX6^y
} SeS ZMv
} |x1Ttr,
else K"g{P
break; 5xnEkg4q4
} IcQpbF0
} <3tf(?*,k]
catch(IOException e){e.printStackTrace ();} :jkPV%!~
catch(Exception e){e.printStackTrace ();} fj(WHL
>k@{NP2b
k5tyOk
Utility.log(nFileLength); []N&,2O
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y c<%f
return nFileLength; 0QquxYYw,
} h82y9($cZ
&WAU[{4W
s2QgR37s>
//保存下载信息（文件指针位置） \8a014
private void write_nPos() Wt!;Y,1s
{ imwn)]LR
try{ o](ORS$~
output = new DataOutputStream(new FileOutputStream(tmpFile)); !IC .0I`
output.writeInt(nStartPos.length); ^iWGGnGS
for(int i=0;i<nStartPos.length;i++) bzZdj6>kX
{ X2| Z!
// output.writeLong(nPos); Bs`='w%7
output.writeLong(fileSplitterFetch.nStartPos); oz:J.<j24Z
output.writeLong(fileSplitterFetch.nEndPos); d3?gh[$
} iH]0 YT.E
output.close(); +JD^5J,-NJ
} HlkjyD8
catch(IOException e){e.printStackTrace ();} &.z-itiV
catch(Exception e){e.printStackTrace ();} 54TWFDmGi
} F/p1?1M
Yu&\a?]\2
FU}- .Ki
//读取保存的下载信息（文件指针位置） X,o ]tgg=
private void read_nPos() GbMu;CA
{ iK'A m.o+
try{ kaR55
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #&S<{75A
int nCount = input.readInt(); B}p.fE
nStartPos = new long[nCount]; "].TKF#yg
nEndPos = new long[nCount]; yfFe%8w_vw
for(int i=0;i<nStartPos.length;i++) .1J`>T?=Q
{ +U<Ae^V
nStartPos = input.readLong(); S*3$1BTl
nEndPos = input.readLong(); \B/( H)Cd*
} (lYC2i_b#
input.close(); WYCDEoqU2
} G8^b9xoA+.
catch(IOException e){e.printStackTrace ();} Pj8Vl)8~NV
catch(Exception e){e.printStackTrace ();} }gX4dv B
} 5/m*Lc+r
Ai)Q(]
Z$YG'p{S
private void processErrorCode(int nErrorCode) <bv9X?U
{ GWj !n
System.err.println("Error Code : " + nErrorCode); T~}g{q,tR
} X/Fip0i
&w%%^ +n |
Pm24;'
//停止文件下载 J(XK%e[8
public void siteStop() nu|odP
{ b%X}{/n
bStop = true; }_Sgor83n
for(int i=0;i<nStartPos.length;i++) i~HS"n
fileSplitterFetch.splitterStop(); mUb2U&6(
[vdC$9z,
q>#P|
} D{[i_K
} Pc~)4>X<
//负责部分文件的抓取 ;]/cCi
**FileSplitterFetch.java JvW!w)$pY
*/ ,Qe`(vU*s
package NetFox; )GC[xo4bg
aO\@5i_r
dUceZmAl
import java.io.*; DshRH>7s8
import java.net.*; :J5CmU$
wLQM]$O
(%M:=zm
public class FileSplitterFetch extends Thread { 9 &Od7Cn
/dVcNo3"
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String sURL; //File URL #M[Cq= 2
long nStartPos; //File Snippet Start Position *K=me/ 3
long nEndPos; //File Snippet End Position R*O6Z"h
int nThreadID; //Thread's ID T5 BoOVgO
boolean bDownOver = false; //Downing is over VK4"
boolean bStop = false; //Stop identical W?12'EG}xa
FileAccessI fileAccessI = null; //File Access interface JlH5 <:#PN
OPKmYzf@b
{+QQ<)l^tJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jRjQDK_"ka
{ Rmh,P>
this.sURL = sURL; <,T#* fg
this.nStartPos = nStart; @eDL j}
this.nEndPos = nEnd; yucbEDO.
nThreadID = id; >LR+dShG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BQ~&gy{
} v{U1B
w{ x=e
QV%eTA
public void run() zhwajc
{ j7Lw(AJ
while(nStartPos < nEndPos && !bStop) lGX_5R
{ v[?eL0Z
FEg&EYI
s8kkf5bu
try{ z*:.maq
URL url = new URL(sURL); =G<S!qW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aw0xi,Jz
httpConnection.setRequestProperty("User-Agent","NetFox"); akA C^:F
String sProperty = "bytes="+nStartPos+"-"; |<7nf75c}
httpConnection.setRequestProperty("RANGE",sProperty); s|8_R;
Utility.log(sProperty); x"PMi[4
&nF7CCF
C F<
InputStream input = httpConnection.getInputStream(); d4-cZw}+
//logResponseHead(httpConnection); .aR$ou,7
<H!;/p/S
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byte[] b = new byte[1024]; P1QGfp0-J
int nRead; RDp(Ci
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hLLg
{ JSiLG0
nStartPos += fileAccessI.write(b,0,nRead); QGd"Z lQ
//if(nThreadID == 1) '^M3g-C[Jg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b*qC
} K<tkNWasQ
8DNGqaH;dt
*,__\/U98
Utility.log("Thread " + nThreadID + " is over!"); ~ +z'pK~c
bDownOver = true; I#hzU8Cc
//nPos = fileAccessI.write (b,0,nRead); ;tLu
} ag$UNV
catch(Exception e){e.printStackTrace ();} lV!@h}mG
} +2]{%=
} w-MnJ(r
%!1:BQ,p,i
+EgQj*F*
//打印回应的头信息 !~k-Sexh
public void logResponseHead(HttpURLConnection con) niN$!k+Jr
{ )Ikx0vDFQ
for(int i=1;;i++) ^?tF'l`
{ >?A3;O]
String header=con.getHeaderFieldKey(i); Lv ,Ls
if(header!=null) (@?PN+68|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 47XQZ-}4
Utility.log(header+" : "+con.getHeaderField(header)); #r)c@?T@j
else "ealYveu
break; P/FO,S-V
} #fYz367>
} bKH8/*Yk
F/w!4,'<?5
.Su9fjy%
public void splitterStop() 'rdg
{ Nl1v*9_x
bStop = true; Jk7[}Jc$
} vg1p{^N!
E8Wgm 8
)f0t"lk
} !Hr +|HKQ?
v 1O* Q
b9([)8
/* S\jN:o#b
**FileAccess.java scUWI"
*//文件访问(定位，写) =X2EF
package NetFox; "U&
import java.io.*; UvOB`Vj
x_\e&"x
l$Y7CIH
public class FileAccessI implements Serializable{ %-:6#bz
8P'>%G<m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C@L:m1fz
RandomAccessFile oSavedFile; ?H3xE=<X
long nPos; _D(F[p|
iffRGnN^e
"ND 7,rQ
public FileAccessI() throws IOException p_QL{gn
{ c>r0N[
this("",0); .)mw~3]
} 9oY%v7
h7 >
uU>Bun
public FileAccessI(String sName,long nPos) throws IOException @$;"nVZ4v
{ sEL[d2oO
oSavedFile = new RandomAccessFile(sName,"rw"); W$P)fPU'
this.nPos = nPos; e p;_'
oSavedFile.seek(nPos); C;;dCsiV5
} pFD L5
-$4PY,
F,`y_71<
public synchronized int write(byte[] b,int nStart,int nLen) -q\1Tlc]3
{ BaTE59W
int n = -1; NQ%lwE~
try{ qMz0R\4
oSavedFile.write(b,nStart,nLen); Wel-a< e
n = nLen; @QMMtfeLj
} 0=&Hm).
catch(IOException e) !K1[o'o#
{ #G^?4Za
e.printStackTrace (); r/fLm8+
} [HK[{M=v=
#Gs] u
5"6Y=AuQ6
return n; [:sV;37s
} $}7/mS@c
-mG3#88*
<D pi M`
} qV.*sdS>
+X0?bVT
i}+K;,Da:8
/* h{kAsd8 G
**SiteInfoBean.java Je+z\eT!5<
*/ !5Kv9P79
package NetFox; pl V]hu27K
+dk}$w[g
QVI4<Rxg
public class SiteInfoBean { $GYcZN&
ep Eg6
W)?B{\
private String sSiteURL; //Site's URL >ZuWsA0q
private String sFilePath; //Saved File's Path NS;,(v{*N
private String sFileName; //Saved File's Name X[}5hZcX
private int nSplitter; //Count of Splited Downloading File uG2Hzav
J(VJMS;_
c:4M|t=
public SiteInfoBean() *K'(t
{//nSplitter的缺省值为5 `$7j:<c=
//default value of nSplitter is 5 O!kBp(?]
this("","","",5); kl_JJX6jPP
} DnP>ed"M!
a&p|>,WS
tD.md_E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |28z4.
{ =h\,-8
sSiteURL= sURL; ;dNKe.`Dg
sFilePath = sPath; cRK1JxU
sFileName = sName; [GX5jD#
this.nSplitter = nSpiltter; 4}Y2 B$
:e`;["(,
~%B^`s
} =M)+O%`*6
u!];RHOp|
1p<m>s=D=e
public String getSSiteURL() Tz]t.]!&E
{ yNP M-
return sSiteURL; Z~ VOO7|m
} ^i2W=A'P
b'4{l[3~nl
dQQh$*IL?{
public void setSSiteURL(String value) pM=@
{ c%yhODq/
sSiteURL = value; K 38e,O
} )"2)r{7:
MJd!J]E6
HP^<2?K
public String getSFilePath() h.E8G^}@
{ /\V-1 7-
return sFilePath; !v;N@C3C
} O{uc h
!jGe_xB}~
,&rlt+wE
public void setSFilePath(String value) ;"$Wfy
{ 0qqk:h
sFilePath = value; 5fMVjd
} 4R0'$Ld4
F$y3oX
$DeHo"mg7m
public String getSFileName() 8e:J{EG~
{ [QEV6S]
return sFileName; F~2bCy[Z
} ) gbns'Z<
$n\{6Rwb
1%68Pnqk
public void setSFileName(String value) ABw:SQ6=Q
{ eme7y
sFileName = value; nj$TdwZbK
} Kur3Gf X
]KdSwIbi
iqm]sC`
public int getNSplitter() VPoA,;Y"-
{ mD<- <]SYp
return nSplitter; #$2{l,>
} n]^zIe^6
ul$k xc=N
e`9d&"
public void setNSplitter(int nCount) 5gYv CW&~
{ hkB/ OJ
nSplitter = nCount; $5N%!
} ],#Xa.r
} Y S/x;
jD1/`g%
;c p*]
/* 'c7C*6;a
**Utility.java f1s3pr??
*/ U{/d dCf7
package NetFox; Z0HfrK#oU
=?]H`T:
BdBwfH%:
public class Utility { @yp#k>
L/\s~*:M
])F*)U
public Utility() *?bOH5$@Nw
{ >G7dw1;
E/[>#%@i
oGt,^!V1
} 1T&NU
{Tx"G9
//线程睡眠 U; -2)+
public static void sleep(int nSecond) >NLG"[\
{ rlxZ,]ul
try{ w5fVug/;P
Thread.sleep(nSecond); #uTNf78X
} _L?MYkD
catch(Exception e) (D2G.R\pr
{ S$#"bK/p^
e.printStackTrace (); t5O '7x
} ?APzb4f^W
} FZL"[3
Gak@Z!|
//日志 X83,fCCl5
public static void log(String sMsg) O2xbHn4
{ 3dO~Na`S
System.err.println(sMsg); uoJ@Jt'j
} K0;caqE^
6g*?(Y][
<pA%|]
public static void log(int sMsg) "&Q sv-9t
{ 2{U5*\FhVX
System.err.println(sMsg); co^bS;r
} `qoRnG
} F8xz^UQO
^mH:8_=(.
To/6=$wto
/* x%h4'Sm
**TestMethod.java W%ml/ 4
*/ 1t+uMhy*y
package NetFox; L6d^e53AP
-@7?N6~qZx
S\76`Ot
public class TestMethod { u~rPqBT{d3
8'WoG]E_
\/XU v(
public TestMethod() %f)%FN.S
{ ///xx/weblogic60b2_win.exe 79&=MTM
try{ C#qF&n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h2jrO9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F\u]X
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z.}Z2K
fileFetch.start(); "+XF'ZO
} kz0pX-@b
catch(Exception e){e.printStackTrace ();} #~}4< 18
-%fc)y&$
gQQve{'
} 8|JPQDS7
8I8{xt4
z`H|]${X
public static void main(String[] args) - +<ai
{ h\T}$jgfWm
new TestMethod(); PGd?c#v#
} J,G/L!Bp
} .R^R32ln
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