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)); =U[3PC-N@
} =/<LSeLxH
for(int i=0;i<nEndPos.length-1;i++) ~pa!w?/bQ
{ `k(yZtb
nEndPos = nStartPos[i+1]; u&G.4QQF
} z"D.Bm~]
nEndPos[nEndPos.length-1] = nFileLength; 0![ +Q4"
} $'W}aER
} w6`9fX6{h
_'4A|-9
Q 4CjA3
//启动子线程 6nhMP$h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )9,
for(int i=0;i<nStartPos.length;i++) HW&%T7 a
{ Li*eGlId
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OY[e.N t&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |6Gm:jV
nStartPos,nEndPos,i); r"$.4@gc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (E,T#uc{
fileSplitterFetch.start(); y@CHR
} P"sA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kq\)MQ"/X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |t$Ma'P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nRd)++
nEndPos = " + nFileLength); I ZQHu h
// fileSplitterFetch[nPos.length-1].start(); kw2T>
.^J2.>.
@FdSFQ/9
//等待子线程结束 Em[DHfu1Q
//int count = 0; "~TA SX_?
//是否结束while循环 a>\vUv*
boolean breakWhile = false; vb9OonE2
8Sz})UZ
oyo(1>
while(!bStop) -i-?.:
{ :qC'$dO!
write_nPos(); vn/.}GkpU
Utility.sleep(500); x@8a''
breakWhile = true; hY`\&@
q -8t'7
\"hJCP?,
for(int i=0;i<nStartPos.length;i++) fhB}9i^]tg
{ dz Zb
if(!fileSplitterFetch.bDownOver) g+X}c/".
{ r(gXoq_w
breakWhile = false; ftH:r_"O#
break; A$6$,h
} }-~l!
} EJ2yO@5O
if(breakWhile) uslQ*7S[^
break; :6$>_m=i
n]he-NHP
,AT[@
//count++; (XoH,K?{z
//if(count>4) vm>b m
// siteStop(); I!^O)4QRx
} O*#*%RL|
nT2)E&U6%
=*Bl|;>6
System.err.println("文件下载结束！"); Yup3^E w&
} B7imV@<
catch(Exception e){e.printStackTrace ();} ?IpLf\n-
} _YRE (YZ/
j&k6O1_
.`&F>o(A
//获得文件长度 $tl\UH7%2
public long getFileSize() y|wc,n%L>
{ av~5l4YL
int nFileLength = -1; |fo0
try{ TsTPj8GAl[
URL url = new URL(siteInfoBean.getSSiteURL()); kwsp9 0)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cph:y
httpConnection.setRequestProperty("User-Agent","NetFox"); 0]4(:(B
qgrg CJ
4!KoFoZt*
int responseCode=httpConnection.getResponseCode(); iTaWup
if(responseCode>=400) NF? vg/{
{ ]kboG%Dl?9
processErrorCode(responseCode); 33}oO,}t,
return -2; //-2 represent access is error l}qE 46EL
} A<ynIs<
M'/aZ# b
i7ly[6{^pr
String sHeader; Tyck/ EO
IH"6? 9nd
Fgh]KQ/5
for(int i=1;;i++) ]~3U
{ 0Zg%+)iy@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +sJrllrE(
//Utility.log(in.readLine()); 4 uQT5
sHeader=httpConnection.getHeaderFieldKey(i); 2@ Z(P.Gh
if(sHeader!=null) twx[s$O'b
{ (IPY^>h
if(sHeader.equals("Content-Length")) Z:_D0jG
{ ()H:UvM=t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jQ)T67
break; e$pMsw'MJ
} .(WQYOMl0
} z0do;_x]E
else `ta7Gc/:UY
break; &@3H%DP}Ql
} -neKuj
} =J~ x
catch(IOException e){e.printStackTrace ();} {,L+1h
catch(Exception e){e.printStackTrace ();} YtWJXkB
/g4f`$a
=ha{Ziryo
Utility.log(nFileLength); &/Q0
p"U,G -_
{.?/)
return nFileLength; ',S'.U
} J.|+ID+
|.3DD"*
Xp}Yw"7
//保存下载信息（文件指针位置） ~T89_L
private void write_nPos() U,.![TP
{ "T- `$'9
try{ (zFi$
output = new DataOutputStream(new FileOutputStream(tmpFile)); E^SH\5B
output.writeInt(nStartPos.length); (!zy{;g|
for(int i=0;i<nStartPos.length;i++) $-*!pRaVU
{ Dmu/RD5X:
// output.writeLong(nPos); <(-hx+^
output.writeLong(fileSplitterFetch.nStartPos); `FC(
output.writeLong(fileSplitterFetch.nEndPos); 5hy""i
} ziCHjqT
output.close(); _"w2Uq
} Xqm::1(-(
catch(IOException e){e.printStackTrace ();} ` 5C~
catch(Exception e){e.printStackTrace ();} qC?:*CXH
} 5kz)5,KjM
x a06i#
82DmG@"s2
//读取保存的下载信息（文件指针位置） =>! Y{: y(
private void read_nPos() EB8\_]6XJ
{ x3"#POp
try{ oGRhnP'PF+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); se>MQM5 )
int nCount = input.readInt(); _}En/V_
nStartPos = new long[nCount]; v3jg~"!
nEndPos = new long[nCount]; WpRc)g:
for(int i=0;i<nStartPos.length;i++) 6Avw-}.7>
{ %&Q$dzgb_
nStartPos = input.readLong(); IDG}ZlG
nEndPos = input.readLong(); 7fba-7-P
} '4#}e[e
input.close(); `6xkf&Kt
} @>U-t{W
catch(IOException e){e.printStackTrace ();} f|tjsZxQ
catch(Exception e){e.printStackTrace ();} B,=H@[Fj
} W!>.$4Q9
7!JQB
fL=~NC"
private void processErrorCode(int nErrorCode) >b{q.
{ H"dJ6
System.err.println("Error Code : " + nErrorCode); q*7VqB
} -#HA"7XOE
Aw5HF34J
{>)#HD
//停止文件下载 ssN6M./6
public void siteStop() E`uY1B[c
{ n@,G8=J?
bStop = true; Xn%pNxUL
for(int i=0;i<nStartPos.length;i++) csW43&
fileSplitterFetch.splitterStop(); FK5<6n,U
_zwG\I|Q
pv Gf\pu
} S-|)QGxV6
} 65aK2MS@
//负责部分文件的抓取 q;][5
**FileSplitterFetch.java xM&Wgei]10
*/ /VN f{p
package NetFox; OD6\Mr2=
#/<&*Pu5t
TO?R({yx*
import java.io.*; [c|]f_ZdK
import java.net.*; 5MtLT#C3r
wlqpn(XR
jGpN,/VQa
public class FileSplitterFetch extends Thread { /*X2c6<d
O4V.11FnW
NP/Gn6fr
String sURL; //File URL 2h1vVF3
long nStartPos; //File Snippet Start Position O%5 r[
long nEndPos; //File Snippet End Position 'DL`Ee\
int nThreadID; //Thread's ID E4~<V=2l
boolean bDownOver = false; //Downing is over 42(Lb'G
boolean bStop = false; //Stop identical ?-dX`n
FileAccessI fileAccessI = null; //File Access interface ,l:ORoND
%~2YE
dE4L=sTEsy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |n,<1QY
{ O\"3J(y,
this.sURL = sURL; 4O)1uF;
this.nStartPos = nStart; HiR[(5vnf
this.nEndPos = nEnd; lrIS{MJ+-
nThreadID = id; Hn%xDJ'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 opy("qH
} DkvF5c&
]dGw2y
pxCK;]
public void run() uF9C-H@:
{ %}Ss,XJ
while(nStartPos < nEndPos && !bStop) pgQV/6
{ Af'" 6BS
p8h9Ng*&`
w1OI4C)~
try{ "AnC?c9?-^
URL url = new URL(sURL); 4,CXJ2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FtfKe"qw
httpConnection.setRequestProperty("User-Agent","NetFox"); B"TAjB& *
String sProperty = "bytes="+nStartPos+"-"; #t:S.A@
httpConnection.setRequestProperty("RANGE",sProperty); 3L_\`Ia9
Utility.log(sProperty); a1t4Dd
U |Jo{(Y
5qZ1FE
InputStream input = httpConnection.getInputStream(); 'E/^8md>
//logResponseHead(httpConnection); 2.l Z:VLN
G IT>L
Jrti cK$
byte[] b = new byte[1024]; *E/`KUG]
int nRead; <SgM@0m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vzdh8)Mu\
{ qln3 k`
nStartPos += fileAccessI.write(b,0,nRead); .<x&IJ /
//if(nThreadID == 1) M<.d8?p )
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cDFO;Dr
} 1 u| wMO
aWWU4xe
-QM: q
Utility.log("Thread " + nThreadID + " is over!"); Po__-xN>Q
bDownOver = true; i|w81p^o
//nPos = fileAccessI.write (b,0,nRead); h_:C+)13`x
} g`vny)\7/
catch(Exception e){e.printStackTrace ();} ;t<QTGJ
} \N!AXD
} <acUKfpY
P"y`A}Bx
9`I _Et
//打印回应的头信息 hbzC#@q
public void logResponseHead(HttpURLConnection con) 544X1Ww2
{ tiB_a}5IB
for(int i=1;;i++) 3DiLk=\~
{ !}v=N";c
String header=con.getHeaderFieldKey(i); 9[b<5Llt
if(header!=null) -Zf@VW,NI
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xjo5v*Pu
Utility.log(header+" : "+con.getHeaderField(header)); \r /ya<5
else z3&]%Q&
break; L+Xc-uv["p
} Tl$[4heE
} - }7e:!.
/y _O4
^W'fA{sr
public void splitterStop() y#Fv+`YDl
{ 6x h:/j3
bStop = true; 10<x.8fSP
} ;1`fC@rI
WN{ 9
87<-kV
} E*.{=W }C
q qpgy7
(]0%}$Fo
/* UR7g`/
**FileAccess.java P3cRl']
*//文件访问(定位，写) [Sr,h0h6
package NetFox; y4*U6+#.
import java.io.*; 2^mJ+v<
C~nzH,5
!/}O>v~o
public class FileAccessI implements Serializable{ P_?gq>E8
WF1px%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "^w]_^GD$d
RandomAccessFile oSavedFile; 8TGOx%}i
long nPos; YVYu:}e3)
`tHvD=`m.
;i Fz?d3;
public FileAccessI() throws IOException :"=ez<t
{ lJu;O/
this("",0); J)`-+}7$v
} B:gjAb}9T
J6U$qi
kSR\RuY*
public FileAccessI(String sName,long nPos) throws IOException +Vm}E0Ov
{ \@8+U;d
oSavedFile = new RandomAccessFile(sName,"rw"); zA$k0p
this.nPos = nPos; _AQb6Nb
oSavedFile.seek(nPos); .QA }u ,EN
} 1u: gFUb
}._eIx"
5&v~i\Q
public synchronized int write(byte[] b,int nStart,int nLen) DE%KW:Hug
{ ^Wc@oa`
int n = -1; <F}_ /q1
try{ {DU`[:SQZg
oSavedFile.write(b,nStart,nLen); A%`[mc]4#
n = nLen; ppZDGpp
} Zb1<:[
catch(IOException e) Tav*+
{ ?Lyxw]
e.printStackTrace (); Q^ pmQ
} _9=Yvc=
Ag&0wN+jTM
k9L?+PD
return n; A9wh(P0\
} LG<J;&41~S
W}5xmz
N'g>MBdI
} b]x4o#t
oJ4AIQjB
m|{3),#V
/* MFb9H{LA
**SiteInfoBean.java H`0|tepz
*/ R~)\3] "2m
package NetFox; XzIl`eH
z"0I>gl
cUvz2TK
public class SiteInfoBean { (+B5|_xQu
*g6n
+R|z{M)*
private String sSiteURL; //Site's URL |h;0H`
private String sFilePath; //Saved File's Path M7@2^G]p
private String sFileName; //Saved File's Name M+w=O!dq
private int nSplitter; //Count of Splited Downloading File h&--,A >
k~jP'aD
jV4\A
public SiteInfoBean() hJZV}a|
{//nSplitter的缺省值为5 i(>4wK!!
//default value of nSplitter is 5 _i20|v
this("","","",5); paKSr|O
} }Q=!Y>Tc
BK,{N0
Bh;7C@dq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iZM+JqfU|D
{ Q$="_y2cTA
sSiteURL= sURL; k +H3Bq
sFilePath = sPath; QWzB6H]
sFileName = sName; JV]^zW
this.nSplitter = nSpiltter; mg*qiScfW
Ry%Mej:
]Bjyi[#bg
} 2oNk93D
A29gz:F(
m^GJuPLW
public String getSSiteURL() :}@g6
{ FW/W%^
return sSiteURL; o]; [R
} @I_8T$N=
iZaI_\"__
y0'Rmk,
public void setSSiteURL(String value) b\-&sM(W"
{ h-Fn?
sSiteURL = value; B[Zjfc
} }>VG~u8
v?& -xH-S
9hOJvQ2U]
public String getSFilePath() H\qC["
{ &!/}Qp
return sFilePath; pXJpK@z
} rzh#CnL3
#m{UrTC
;)!Sp:mHX
public void setSFilePath(String value) X&0 uI*r
{ G|( ]bvJ?
sFilePath = value; p' +
} Gcig*5
l,,>& F
X!m9lV<
public String getSFileName() V??dYB(
{ Lz:(6`S
return sFileName; *T~Ve;3h;
} $aN&nhoO<
Mi/&f
+TQ47Zc
public void setSFileName(String value) :1iqT)&|8F
{ ^sVX)%
sFileName = value; p TeOW9
} Kwg4sr5"D
!-,t'GF(
-eN\ !
public int getNSplitter() WC|.g,9#
{ *7h!w!LN~
return nSplitter; 7LU}Iiv
} dO4{|(z
6Qx#%,U^ J
;ByOth|9P
public void setNSplitter(int nCount) k&.Jk B"
{ ui@2s;1t
nSplitter = nCount; }b0; 0j
} "V$Bnz\n
} |jVM&R2s
l?Fb ='#
7 <Q5;J&;
/* ;\\@q"n%<
**Utility.java FDv+*sZ
*/ *0>mB
package NetFox; ,iv|Pq$!
2w-51tqm
I=.z+#Y
public class Utility { ZG du|
,i,q!M{-
cPU/tkc
public Utility() =n' 4?W@
{ E4W zU
LJ(1RK GCz
C,pJ`:P
} T7d9ChU\#.
i6 (a@KRY
//线程睡眠 u*#ZXW
public static void sleep(int nSecond) y:vxE8$Q
{ Kbb78S30
try{ =T7A]U]
Thread.sleep(nSecond); %bD}m!
} L
catch(Exception e) `/MvQ/
{ }A:<%N
e.printStackTrace (); ~~6^Sh60g
} fz3lV
} |-CnT:|o
\#>T~.Y7K
//日志 viAMr"z
public static void log(String sMsg) a<A+4uXyD
{ W5'3$,X9
System.err.println(sMsg); ,E$@=1)
} A?oXqb
k~|-gfFP
}irn'`I
public static void log(int sMsg) 4#'("#R
{ s#S%#LM
System.err.println(sMsg); iK IOh('G
} U7DCx=B
} ,~);EC=`
i9D0]3/>
}=2;
/* nWvuaQ0}
**TestMethod.java Bs MuQ|!
*/ xwH?0/
package NetFox; 6y5A"-
/LM4-S
-.|4Y#b:&
public class TestMethod { DS-fjH\
}rdIUlVO\
)C.yF)Ql
public TestMethod() 0'r%,0
{ ///xx/weblogic60b2_win.exe U5]pi+r
try{ gBf4's
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u<n`x6gL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3<?XTv-
SiteFileFetch fileFetch = new SiteFileFetch(bean); cM_Fp
fileFetch.start(); bhs(Qzx
} O3.C:?;x
catch(Exception e){e.printStackTrace ();} sIl33kmv
-[Qvg49jy
V >,Z-&.%
} ;_:Ool,
!4rPv\
M- 0i7%
public static void main(String[] args) #2tCV't
{ m4[g6pNx~
new TestMethod(); xc?}TPpt
} <g9"Cr`
} w^1Fi8+
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