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)); 3Zz_wr6
} dr8Q>(ZY
for(int i=0;i<nEndPos.length-1;i++) %U<lS.i
{ 7u1o>a%9
nEndPos = nStartPos[i+1]; hQ)?LPUB
} g}?39?o4
nEndPos[nEndPos.length-1] = nFileLength; 8eCh5*_$
} amQiH!}8R
} H>\lE2
SA"4|#3>7
,LOx!
//启动子线程 "T8b.ng
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; daB5E<?
for(int i=0;i<nStartPos.length;i++) eMOp}.zt|
{ _4{3^QZq5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i*xVD`x~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C9Cl$yZ
nStartPos,nEndPos,i); x wfdJ(&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >0:=<RW
fileSplitterFetch.start(); |+-b#Sa9
} Nog{w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3nq4Y'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3"HEXJMc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sw{rNzh%$
nEndPos = " + nFileLength); C:!&g~{cKi
// fileSplitterFetch[nPos.length-1].start(); X#W6;?Z\
B|>eKI
uYE"OUNWL
//等待子线程结束 QVb{+`.7
//int count = 0; ju.`c->k"
//是否结束while循环 x {Rj2~KC
boolean breakWhile = false; ? _[q{i{
*P12d
r-hb]!t
while(!bStop) eH;{Ln
{ 6m9\0)R
write_nPos(); ![[:Z
Utility.sleep(500); #E/|WT
breakWhile = true; !4"$O@U4
f1\mE~#}
<?rdhx
for(int i=0;i<nStartPos.length;i++) P!R`b9_U
{ )C#>@W
if(!fileSplitterFetch.bDownOver) o~x49%X<c
{ b\SB
breakWhile = false; BE!WCDg,
break; fo;^Jg.
} $3Sm?
} SG)|4$"
if(breakWhile) VkC1\L6
break; aO *][;0
O2~Q(q'
qwuA[QkPi
//count++; wemhP8!gc
//if(count>4) wA";N=i=
// siteStop(); 2 o5u02x
} UotLJa
_BND{MsX
uF@DJX}>
System.err.println("文件下载结束！"); 9'O@8KB_
} za5E{<0
catch(Exception e){e.printStackTrace ();} E`q)vk
} /6'5uP
\lpvRZ\L&g
X<:Zx#J?i
//获得文件长度 JF9r[%
public long getFileSize() U5;Y o+z
{ 2()/l9.O'
int nFileLength = -1; ov Wm}!r
try{ $btk48a7
URL url = new URL(siteInfoBean.getSSiteURL()); Hy2~D:34
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $*+`;PG-
httpConnection.setRequestProperty("User-Agent","NetFox"); ^%RIz!}
Nf9$q| %!
i)MJP*
int responseCode=httpConnection.getResponseCode(); o=Kd9I#
if(responseCode>=400) i=`@)E
{ (p?B=
processErrorCode(responseCode); aB~=WWLR\
return -2; //-2 represent access is error 4^K<RSYs
} 7HQ|3rt
a_Z[@W
l7S&s&W @
String sHeader; u[LsH
z?g\w6
?[hkh8|
for(int i=1;;i++) 6z1>(Za7>
{ xY`$j'u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O.'\GM
//Utility.log(in.readLine()); f5vsxP)Y[
sHeader=httpConnection.getHeaderFieldKey(i); 7HEUmKb"
if(sHeader!=null) F'JceU
{ |BE`ASW;
if(sHeader.equals("Content-Length")) 5H/D~hr&
{ =.6JvX<d1*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $w ,^q+
break; W[oQp2 =
} <iznB8@
} Aw7_diK^
else oGqbk x
break; njBK{
} 5c6?$v/
} W4S! rU
catch(IOException e){e.printStackTrace ();} hD>cxo
catch(Exception e){e.printStackTrace ();} @SH$QUM(
= GZ,P (
Y #6G&)M
Utility.log(nFileLength); rI;tMNs
hBNA,e:
pcO0xrI
return nFileLength; nY50dFA,
} 4Y4QR[>IU3
x10u?@
[BKX$A:Y
//保存下载信息（文件指针位置） q;=!=aRg
private void write_nPos() DjveMs$d
{ \LQ54^eB
try{ NaYr$`
output = new DataOutputStream(new FileOutputStream(tmpFile)); )CUB7D)=
output.writeInt(nStartPos.length); fHR^?\VVp
for(int i=0;i<nStartPos.length;i++) #^eXnhj9
{ %g{<EuK]p
// output.writeLong(nPos); [vyi_0[
output.writeLong(fileSplitterFetch.nStartPos); XmX{e.<NZ
output.writeLong(fileSplitterFetch.nEndPos); SH/^qDT'
} 5.zv0tJku
output.close(); ,K~r':ht
} LV!<vakCK
catch(IOException e){e.printStackTrace ();} Mib<1ZM
catch(Exception e){e.printStackTrace ();} eeu;A,@U
} &BS*C} },
Y>Tok|PV
xJ|_R,>.H
//读取保存的下载信息（文件指针位置） :|PgGhW
private void read_nPos() BoHpfx1C
{ F<LRo}j"9Q
try{ %e%VHHO|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B4 +A
int nCount = input.readInt(); V"DilV$v
nStartPos = new long[nCount]; fsz:A"0H
nEndPos = new long[nCount]; |.Vs(0O
for(int i=0;i<nStartPos.length;i++) {bD:OF
{ Auk#pO#
nStartPos = input.readLong(); vG'I|OWg
nEndPos = input.readLong(); 5VhJ*^R`y
} mo
input.close(); -wrVhCd~g]
} mq6TwM
catch(IOException e){e.printStackTrace ();} vj hh4$k
catch(Exception e){e.printStackTrace ();} l#cG#-
} d_aHUmI^"
9L9qLF5 t
Z|6,*XEc
private void processErrorCode(int nErrorCode) G%5ZG$as
{ ['jr+gIfQ
System.err.println("Error Code : " + nErrorCode); ~x6<A\
} b>x03%
crl"Ec
z6x`O-\
//停止文件下载 ;\(X;kQi
public void siteStop() Q7@oAeNd
{ S\R5SRE
bStop = true; @M&qH[tK-A
for(int i=0;i<nStartPos.length;i++) 2pmqP-pKd
fileSplitterFetch.splitterStop(); 4c9a"v
PB?92py&
WO!'("
} v$~$_K
} t+Au6/Dx?
//负责部分文件的抓取 rBUWzpE"
**FileSplitterFetch.java )];Bo.QA
*/ E_-QGE/1
package NetFox; $(+#$F<eo+
IaT\ymm`
?4cj"i
import java.io.*; -OXC;y
import java.net.*; {@ Z=b5/P
N~~ sM"n
E{BX $R_8
public class FileSplitterFetch extends Thread { ?Sr7c|a2
W^YaC (I
]\m>N]P]
String sURL; //File URL yS1i$[JV
long nStartPos; //File Snippet Start Position X.+|o@G
long nEndPos; //File Snippet End Position / }Pj^^6A<
int nThreadID; //Thread's ID y;<F|zIm
boolean bDownOver = false; //Downing is over E<sd\~~A:
boolean bStop = false; //Stop identical l1vI
FileAccessI fileAccessI = null; //File Access interface N;gY5;0m
i ?PgYk&}
M;9s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z rv:uEl
{ spT$}F2n
this.sURL = sURL; ==AmL]*
this.nStartPos = nStart; }#h`1 uV
this.nEndPos = nEnd; yw1-4*$c
nThreadID = id; Cy dV$!&mP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IG&twJR
} {mUt|m7!
M+*K-zt0
![9$ru
public void run() {2k]$|
{ +kN,OK~
while(nStartPos < nEndPos && !bStop) 'xLXj>
{ uS5G(}[
E0AbVa.
X;n09 L`CB
try{ Fw:_O2
URL url = new URL(sURL); -^3uQa<zN^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @C%6Wo4l3
httpConnection.setRequestProperty("User-Agent","NetFox"); %JgdLnQE
String sProperty = "bytes="+nStartPos+"-"; ;;6$d{
httpConnection.setRequestProperty("RANGE",sProperty); /_qHF-
Utility.log(sProperty); udXzsY9Ng
C]Y%dQh+a
e+V8I&%
InputStream input = httpConnection.getInputStream(); =3ovaP
//logResponseHead(httpConnection); 33; '6/
=X9fn
ZZL@UO>:
byte[] b = new byte[1024]; <<b]v I
int nRead; E]v?:!!ds
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?GlXxx=eV
{ #^BttI
nStartPos += fileAccessI.write(b,0,nRead); TB-dV'w
//if(nThreadID == 1) KY}H-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0' oXA'L-J
} bYoBJ #UX
F-$!e?,H
!FDd5CS
Utility.log("Thread " + nThreadID + " is over!"); Z~<=I }@
bDownOver = true; ?J,,RK.
//nPos = fileAccessI.write (b,0,nRead); F{.\i*$
} TMo DN%{
catch(Exception e){e.printStackTrace ();} )ki Gk}2
} 3H0B+F2XQ
} ^/6P~iK'
K8Q3~bMf
w$Fg0JS
//打印回应的头信息 { 0-on"o
public void logResponseHead(HttpURLConnection con) -Lu&bVt<>
{ m"'}{3$%
for(int i=1;;i++) +*Z'oCBJ,
{ !^ad{#|X
String header=con.getHeaderFieldKey(i); -7]j[{?w
if(header!=null) SZyORN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PZ`11#bbm
Utility.log(header+" : "+con.getHeaderField(header)); $dXx@6fP
else yCA8/)>Gm
break; ~\8(+qIv%f
} r~2hTie
} BjagG/sX
k|\M(Z*(P
[`oVMR
public void splitterStop() ]ly" K!1,
{ pu+Q3NfR
bStop = true; f*B-aj#
} ~D>pu%F
oda,
%T\hL\L?
} &b`W<PAc?4
PCHspe9!y
M:{Aq&.
/* Ei):\,Nv
**FileAccess.java &e@)yVLL
*//文件访问(定位，写) * 70ZAo4
package NetFox; {x.0Yh7
import java.io.*; ^a_a%ws
IlB8~{p_
y/c3x*l.xL
public class FileAccessI implements Serializable{ J (?qk
jT=|!,Pn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R-j*fO}
RandomAccessFile oSavedFile; Wz s=BNm9
long nPos; |[IyqWG9
No} U[u.O
z&tC5]#
public FileAccessI() throws IOException n)98NSVDbT
{ T"W<l4i-
this("",0); SXZ9+<\
} L;%w{,Ji
y'`/^>.
MCmb/.&wu
public FileAccessI(String sName,long nPos) throws IOException B(++*#T!^m
{ \agZD+
oSavedFile = new RandomAccessFile(sName,"rw"); 'v~'NWfd
this.nPos = nPos; rBNVI;JZW
oSavedFile.seek(nPos); `.@sux!lu
} 5tQz!M
[jzsB:;XB&
n jWe^
public synchronized int write(byte[] b,int nStart,int nLen) kFWwz^x
{ >ep<W<b
int n = -1; eKvr1m- -
try{ oT):#,s
oSavedFile.write(b,nStart,nLen); 5'I+%66?h$
n = nLen; iVI&
} su1lv#
catch(IOException e) );7 d_#
{ B#Ybdp ;
e.printStackTrace (); oQ<[`.s
} D4!;*2t
FOsd{Fw
dZ`Y>wH_
return n; P_1WJ
} %Hbq3U30
Qh1pX}X
#T_!-;(Z
} 0\tac/
2{rWAPHgz
{5E8eQ
/* @-!P1]V|
**SiteInfoBean.java Yub}AuU`v
*/ #c^]p/
package NetFox; iWf+wC|
f=F:Af!
cmG27\cRO
public class SiteInfoBean { Xxg|01
NZvgkci_(u
[`\VgKeu
private String sSiteURL; //Site's URL )[Tm[o?Y.
private String sFilePath; //Saved File's Path Y\]ZIvTSb
private String sFileName; //Saved File's Name |IcW7(
private int nSplitter; //Count of Splited Downloading File nHdQe
*/;7Uv7
=GX5T(P8k
public SiteInfoBean() 6dIPgie3w
{//nSplitter的缺省值为5 *-nO,K>y`
//default value of nSplitter is 5 5^g*
this("","","",5); gZ,h95'
} %;'~TtW5
loVg{N:
'Cc~|gOgD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $gUlM+sK
{ 8_('[89m
sSiteURL= sURL; v76Gwu$d
sFilePath = sPath; q5(t2nNb
sFileName = sName; &>JP.//spi
this.nSplitter = nSpiltter; QRQZ{m
lmeTW0U@9(
[Yt{h9
} Z}+}X|
E!9WZY
r].n=455[
public String getSSiteURL() FCEy1^u
{ .4+Rac
return sSiteURL; q?}C`5%D
} }=-0DSLVj
keAoJeG,J
f% pT-#
public void setSSiteURL(String value) 6.D|\;9{c
{ Jl{ 0q7b
sSiteURL = value; _Si=Jp][
} S^rf^%
!D??Y^6bI
V`I4"}M1
public String getSFilePath() /$c87\
{ VQ9A/DH/
return sFilePath; dQ`Tt- n
} +RooU?Aq
U^dfNi@q
B>53+GyMV
public void setSFilePath(String value) m+(Cl#+
{ uM2@&)u
sFilePath = value; %O\@rws
} v;]rFc#Px[
;U* /\+*h
f^F;`;z
public String getSFileName() 981-[ga`Y
{ |:eTo<
return sFileName; 5XKTb
} ,PlH|
`_\KN_-%Vu
(/]'e}
public void setSFileName(String value) FIq'W:q:
{ FLi'}C
sFileName = value; nfEbu4|
} U{2xgNJ
9!( 8o
qf? "v;
public int getNSplitter() Bj@>iw?g'
{ Sm'Tz&!
return nSplitter; p'jc=bL E
} X-["{
Q %o@s3~O
$k~TVm Yex
public void setNSplitter(int nCount) JK/{IkF
{ ]oGd,v X
nSplitter = nCount; rW?WdEg
} <[dcIw<7
} xM jn=\}
Ta?J;&<u]/
NEq_!!/sF
/* (:l6R9'=
**Utility.java 3TwjC:Yhv2
*/ eRMN=qP.q
package NetFox; 6 >kULp
!rnjmc
CS[]T9|_
public class Utility { Q|_F P:
;.}L#'0j
JxVGzb`8
public Utility() Ju+3}
{ :60vbO
}_+XN"}C
qDdO-fPev
} MLDzWZ~}ef
NW\CEJV
//线程睡眠 ,.)wCZ,wca
public static void sleep(int nSecond) X$kLBG[o_
{ Pe%[d[k
try{ Olzw)WjG
Thread.sleep(nSecond); <pX?x3-'
} $f:uBhM
catch(Exception e) T@W:@,34
{ _pdKcE\X
e.printStackTrace (); _U~R
} 7@c!4hmrU
} XM]m%I
rNN>tpZ}
//日志 T<]{:\*n
public static void log(String sMsg) ?mH=3 :~
{ 2!%)_<
System.err.println(sMsg); pBqf+}g4
} DGFSD Py[
J*B-*6O44
VEWW[T
public static void log(int sMsg) ?m)<kY
{ kQ+y9@=/g
System.err.println(sMsg); h"[B zX
} }3z3GU8Q-
} G$C2?|V)=
u$?!
?_H9>/:.
/* 8\{!*?9!
**TestMethod.java DAw1S$dM
*/ *;Kp"j
package NetFox; p3P8@M
- (s0f
Xqf\}p n
public class TestMethod { JA^!i98{
SQ)BS/8A
"%T~d[M
public TestMethod() hj];a,Br&
{ ///xx/weblogic60b2_win.exe "kApGNB
try{ G2`YZ\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;0eVE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5AT^puL]]
SiteFileFetch fileFetch = new SiteFileFetch(bean); QFnuu-82"
fileFetch.start(); qT?{}I
} !Yc:yF
catch(Exception e){e.printStackTrace ();} {t;o^pUF
M7BpOmK'
Y1cL dQn
} .vHHw@
5 3pW:`
:>!-[hfQ
public static void main(String[] args) L;:|bVH
{ %Z6Q/+#fn
new TestMethod(); 'bbw0aB4
} ]*NYuEgc
} 8R)K$J$Hm
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