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_}_)nE@m
} =:Yrb2gP_\
for(int i=0;i<nEndPos.length-1;i++) !>"fDz<w`
{ lUaJC'~p
nEndPos = nStartPos[i+1]; HOx+umjxW
} v8WT?%
nEndPos[nEndPos.length-1] = nFileLength; bsm/y+R
} ]bAVOKm-
} F @<h:VVP
Sgr. V)
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//启动子线程 H|0-Al.{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 734t
for(int i=0;i<nStartPos.length;i++) ,>01Cs=t8
{ Y]=k"]:%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +?W4ac1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q`'"+`h
nStartPos,nEndPos,i); n!.=05OtX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qcouZO
fileSplitterFetch.start(); (/0dtJ
} xFekSH7[F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \>>P%EU,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e/_QS}OA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FrUqfTi+W
nEndPos = " + nFileLength); ZPY&q&R
// fileSplitterFetch[nPos.length-1].start(); 6:L2oW 6}{
`a:3S@n(}
K@JaN/OM
//等待子线程结束 AAs&P+;
//int count = 0; S*>T%#F6Uo
//是否结束while循环 jV9oTH-
boolean breakWhile = false; SB08-G2
sa&`CEa
O) TS$
while(!bStop) !Vg=l[
{ K3<A<&W_-
write_nPos(); ZjMnGRP
Utility.sleep(500); 6D[]Jf,9
breakWhile = true; w3"L5;oH
_yUYEq<`
:s&dn%5N"
for(int i=0;i<nStartPos.length;i++) <YtjE!2
{ f>$RR_
if(!fileSplitterFetch.bDownOver) y3o3G
{ <&3aP}
breakWhile = false; jDqG9]
break; Ef?hkq7X<
} hdi0YL
} x{8h3.ZQ,
if(breakWhile) r#2Fk&Z9
break; UKZ)Boo
.4U*.Rf
mNacLkh[
//count++; j)Ak:l%a
//if(count>4) ;3wO1'=
// siteStop(); nw%9Qw
} uSRhIKy
qljsoDG
KK #E qJ
System.err.println("文件下载结束！"); Osm))Ua(
} 1%*\*z
catch(Exception e){e.printStackTrace ();} =EMB~i
} __Ksn^I
T]Ai{@i
D>7J[ Yxg-
//获得文件长度 2nC,1%kxhq
public long getFileSize() GVJ||0D
{ mICEJ\`x
int nFileLength = -1; H\a"=&M
try{ *9$SFe|&n:
URL url = new URL(siteInfoBean.getSSiteURL()); M /v@C*c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~=iH*AQR
httpConnection.setRequestProperty("User-Agent","NetFox"); z)U7
)MK$E,W
:o{,F7(P
int responseCode=httpConnection.getResponseCode(); oPr`SYB
if(responseCode>=400) ;*<R~HJt
{ 1S!}su,uH
processErrorCode(responseCode); tkcs6uy
return -2; //-2 represent access is error ?.%dQ0
} RPgz"-
+llb{~ZN
CN:T$ f|)
String sHeader; IF0!@f
NT.#U?9c
Z;81"
for(int i=1;;i++) `3i>e<m~
{ MkoK(m{7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'WE"$1
//Utility.log(in.readLine()); 2{63:f1c`'
sHeader=httpConnection.getHeaderFieldKey(i); Rh|9F yN
if(sHeader!=null) j\~,Gtn>Z
{ -'d:~:1f
if(sHeader.equals("Content-Length")) ?l?l<`sTO
{ EUuSN| a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,7Hyrx`
break; mLZ1u\7W
} k Alxm{
} -i2rcH
else Ge-Bk)6
break; )wM%Ul<s
} mXp#6'a
} +|obU9M
catch(IOException e){e.printStackTrace ();} 3PU_STSix
catch(Exception e){e.printStackTrace ();} EwN{|34C
8(\}\4G_
2@6@|jRG
Utility.log(nFileLength); {+WY,%e
#\lvzMjCC
H)D|lt5xy
return nFileLength; fF0i^E<
} Tt)z[^)%
{V QGfN
b+|Jw\k
//保存下载信息（文件指针位置） r9_ ON|
private void write_nPos() M.mn9kw`
{ Fk/I (Q
try{ vw2E$ya
output = new DataOutputStream(new FileOutputStream(tmpFile)); hXjZ>n``
output.writeInt(nStartPos.length); k9rws
for(int i=0;i<nStartPos.length;i++) <C'_:&M
{ hYkkr&
// output.writeLong(nPos); Bgm8IK)6
output.writeLong(fileSplitterFetch.nStartPos); JfN5#+_i
output.writeLong(fileSplitterFetch.nEndPos); QLO;D)fC
} =){G
output.close(); R}0gIp=
} 1WMZ$vsQUb
catch(IOException e){e.printStackTrace ();} _f%s]
catch(Exception e){e.printStackTrace ();} -`k>(\Q<d
} ;pW8a?
8{G!OBxc\.
cRnDAn#42
//读取保存的下载信息（文件指针位置） 4@-tT;$
private void read_nPos() Jj \nye+
{ OOSf<I*>
try{ _C/|<Ot:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7@;*e=v
int nCount = input.readInt(); ['}|#3*w
nStartPos = new long[nCount]; zas&gsl-;
nEndPos = new long[nCount]; %[p*6&V
for(int i=0;i<nStartPos.length;i++) A`3KE9ED
{ g9pKoi|\E
nStartPos = input.readLong(); 6LDZ|K@
nEndPos = input.readLong(); JU>~[yAP
} _s^tL2Pc
input.close(); $#hU_vr
} plWNuEW
catch(IOException e){e.printStackTrace ();} #EzhtuHxn
catch(Exception e){e.printStackTrace ();} $vXY"-k
} -t4:%-wv
FFw(`[A_
e#;43=/Ia
private void processErrorCode(int nErrorCode) ]eGa_Ld
{ ` 7iA?;
System.err.println("Error Code : " + nErrorCode); ]"T157F
} QPf\lN/$4d
%0-oZL
@o0HDS
//停止文件下载 #a}w&O";
public void siteStop() lu{ *]!
{ Gky*EY
bStop = true; R1LirZlzJ
for(int i=0;i<nStartPos.length;i++) QIkFX.^
fileSplitterFetch.splitterStop(); jo"nK,r
@sn:%/x_
ZvF#J_%gE5
} ~},H+A!?
} _|C3\x1c
//负责部分文件的抓取 2@a'n@-
**FileSplitterFetch.java ELwXp|L
*/ 6Mc&=}bV
package NetFox; /1LN\Eu
M#^q <K %
zRjbEL
import java.io.*; = cxO@Fu
import java.net.*; MlWKfe<
_W(xO |,M
'QE8
public class FileSplitterFetch extends Thread { Q I";[
co\?SgE35
\xS X'/G
String sURL; //File URL `S((F|Ty=;
long nStartPos; //File Snippet Start Position n/;{-
long nEndPos; //File Snippet End Position zKP[]S-
int nThreadID; //Thread's ID ]xvhUv!G
boolean bDownOver = false; //Downing is over s&ox%L4
boolean bStop = false; //Stop identical On);SN'
FileAccessI fileAccessI = null; //File Access interface ? /!Fv/
'~b
DH\Ox>b=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {@KLN<
{ LeN }Q
this.sURL = sURL; *P *.'XM
this.nStartPos = nStart; A(&\wd
this.nEndPos = nEnd; a)2l9
nThreadID = id; <tTNtBb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @GAj%MK$
} iOa<=
$!G|+OuTR
{0j,U\ kb
public void run() }%wP^6G*x\
{ rIPg,4y*S!
while(nStartPos < nEndPos && !bStop) \|X 1
{ fX9b1x
1<x5{/CZ
;woK96"{t
try{ v0WB.`rO
URL url = new URL(sURL); ?z)2\D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +q2\3REzx
httpConnection.setRequestProperty("User-Agent","NetFox"); uu4!e{K
String sProperty = "bytes="+nStartPos+"-"; 2pHR$GZ2
httpConnection.setRequestProperty("RANGE",sProperty); Flpl,|n a
Utility.log(sProperty); ?}^ y6
zk70D_}L
XH0{|#hwN
InputStream input = httpConnection.getInputStream(); ++w{)Io Z
//logResponseHead(httpConnection); zhE4:g9v
\zVp8MMf
M&zB&Ia"'
byte[] b = new byte[1024]; L9hL@
int nRead; unYPvrd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sk5=$My
{ ,-d2wzhW
nStartPos += fileAccessI.write(b,0,nRead); 8fvKVS
//if(nThreadID == 1) 78T;b7!-C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d?U,}tv
} 5-a^Frmg#"
QncjSaEE
E]{0lG`l
Utility.log("Thread " + nThreadID + " is over!"); Yo5ged]i
bDownOver = true; LUx'Dm"
//nPos = fileAccessI.write (b,0,nRead); #I ,c'Vj
} L(y~ ,Kc
catch(Exception e){e.printStackTrace ();} pOy(XUV9O
} z,qNuv"W
} UGOe(JB
|Qpo[E}a
F":dS-u&L
//打印回应的头信息 K=sk1<>)m
public void logResponseHead(HttpURLConnection con) _n*gj-
{ >hnhV6ss
for(int i=1;;i++) 6jal5<H
{ ) \cnz
String header=con.getHeaderFieldKey(i); ^*NOG\BK@
if(header!=null) Sr6iQxE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mv%B#J
Utility.log(header+" : "+con.getHeaderField(header)); 0,LUi*10
else &6Wim<*
break; H'2o84$
} \bSakh71
} 78mJ3/?rC
S@L%X<Vm
Q|Pm8{8
public void splitterStop() ^^Q>AfTR.
{ k"`^vV[{F
bStop = true; ]G~u8HPH!m
} G#^6H]`[J:
KC\W6|NtGj
\ ]h$8JwV
} P_N},Xry
:rmi8!o
6:TA8w|
/* s[*I210
**FileAccess.java `? f sU
*//文件访问(定位，写) PPtJ/ }\
package NetFox; KU0;}GSNX}
import java.io.*; VS<w:{*
6;\Tps;A
iEBxBsz_
public class FileAccessI implements Serializable{ =~j S
hniTMO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Su`] ku'
RandomAccessFile oSavedFile; |fWR[\NU
long nPos; cT^x^%
}l@7t&T|
*7/MeE6)i
public FileAccessI() throws IOException Ils^t
{ ZP7wS
this("",0); 1\Vp[^#Vx
} Yh;A
.*w3ryQ
Zv1/J}+
public FileAccessI(String sName,long nPos) throws IOException BO=j*.YKy
{ m[*y9A1
oSavedFile = new RandomAccessFile(sName,"rw"); UXV>#U?
this.nPos = nPos; cX-)]D
oSavedFile.seek(nPos); /SYzo4(
} [;i3o?\_I
,G(bwE9~
K"ytE2:3
public synchronized int write(byte[] b,int nStart,int nLen) e/u(Re
{ r)t-_p37
int n = -1; Xc@%_6
try{ 4EEXt<c.
oSavedFile.write(b,nStart,nLen); 7tz#R:
n = nLen; _S#3!Wx
} &l1CE19<
catch(IOException e) |-k~Fa
{ EPwM+#|e-
e.printStackTrace (); s av
} aruT eJF
0--0+?
FZhjI 8+,~
return n; !_UBw7Zm
} <</ Le%
qc`UDD5
3P2L phW
} g JMv
f0lK,U@P
ns[Q %_
/* cn!Y7LVr
**SiteInfoBean.java k7Z1Y!n7
*/ q\6ZmKGnT
package NetFox; Lv?e[GA
)OcG$H NK
*l4`2eqZ
public class SiteInfoBean { % 2lcc"'
('.r_F
rN^P//
private String sSiteURL; //Site's URL 7Cj6Kw5k
private String sFilePath; //Saved File's Path _-g?6q
private String sFileName; //Saved File's Name @=1kr ^i
private int nSplitter; //Count of Splited Downloading File 9gokTFoN
%phv<AW
Nt'u;0
public SiteInfoBean() q+-Bl
{//nSplitter的缺省值为5 Syj7K*,%bZ
//default value of nSplitter is 5 -%x9^oQwY
this("","","",5); |CFTOe\q
} =:-x;
(*2kM|
bfjtNF*^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *z A1NH5
{ S7 Tem:/
sSiteURL= sURL; 2r=A'
sFilePath = sPath; v'zf*]9
sFileName = sName; !EQMTF=(
this.nSplitter = nSpiltter; v(tr:[V
<+c6CM$#}V
7&z`N^dz{
} B}y-zj;T
9>"To
;eeu 9_$
public String getSSiteURL() f#9\&-he0
{ m^)h/s0A
return sSiteURL; lE?F Wt
} (7g1eEK%
c);(+b
7Q9zEd"d
public void setSSiteURL(String value) Ll L8Q
{ `cgSyRD]
sSiteURL = value; i`1QR@11
} A[6$'IJ
CdRgI^5
lU<n Wf
public String getSFilePath() `n!<h,S'2
{ #Mz N7
return sFilePath; "K8<X
} E}$K&<J'-
-l!;PV S|
[=Yfdh M8S
public void setSFilePath(String value) kEQ${F{
{ Wh)QCp0|n
sFilePath = value; X>#!s Lt
} 7QlA/iKqK
5!PU+9Kh
F*_mHYa;
public String getSFileName() H[{ch t h
{ \5%T'S@5
return sFileName; 0r+%5}|-K
} l%^'K%'b
:hp=>^$Y
/L1qdkG
public void setSFileName(String value) WBA0! g98
{ F:CqB|
sFileName = value; dB`YvKr#
} P==rY5+s`
;,y9
46dh@&U
public int getNSplitter() EnrRnVB
{ '~E&^K5hr
return nSplitter; 5UwaBPj4
} q lL6wzq,
Iky'x[p,D
,!f*OWnZ
public void setNSplitter(int nCount) >4.{|0%ut
{ he/UvMu
nSplitter = nCount; ^AUmIyf_
} [Uezi1I
} PF1m :Iz`d
zX!zG<<K
A}b<Lg
/* otXB:a
**Utility.java P(W7,GD,k
*/ /R< Q~G|\
package NetFox; xOjCF&W
=J,aBp
cvbv\G'aT
public class Utility { -,~n|ceI
(d[)U<
j0k"iv
public Utility() AR?J[e
{ Nvs8t%
"~4ULl<i'
&Q^M[X
} `n7z+
\HDRr*KO
//线程睡眠 Y>+\:O
public static void sleep(int nSecond) 6P' m0
{ <3QE3;4
try{ G1Cn[F;e
Thread.sleep(nSecond); }0T1* .Cz
} f4zd(J
catch(Exception e) !9i,V{$c`"
{ :<s)QD
e.printStackTrace (); iuq-M?1
} GP uAIoBo
} i`Es7 }
}`yIO"{8n
//日志 :JqH.Sqk
public static void log(String sMsg) Cl]E rg
{ ~?dPF;.6_
System.err.println(sMsg); im_W0tGvF
} S >uzW #
9q;\;-
#zXkg[J6d
public static void log(int sMsg) vcAs!ls+
{ 5-}4jwk
System.err.println(sMsg); Bya!pzbpr
} fAfsKO*
} C}+w<
5>7ECe*
UGEC_
/* R{3f5**0
**TestMethod.java jGEUl=W
*/ j3~:\H
package NetFox; >(u=/pp=:
Fy<dk}@
$CO^dFf
public class TestMethod { "-vm=d~\
}}Eko7'^
J(S.iTD
public TestMethod() CJ&0<Z}{m
{ ///xx/weblogic60b2_win.exe l.lXto.6)
try{ V$-IRdb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); APuG8 <R,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B[Uvj~g
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0W9,uC2:N
fileFetch.start(); ;|b D@%@
} xF5q=%n
catch(Exception e){e.printStackTrace ();} R1X9
Jk|c!,!
`Bnp/9q5
} \A _g
+is;$1rq
N>7INK
public static void main(String[] args) `RfhxzI
{ cgm]{[f
new TestMethod(); ]~)FMWQz-
} _odP:
} /_?Ly$>'
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