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)); jVIpbG44
} 5XI*I(.%/
for(int i=0;i<nEndPos.length-1;i++) A.O~'')X
{ ^mpB\D)q
nEndPos = nStartPos[i+1]; @UX@puK`/
} ;vdgF
nEndPos[nEndPos.length-1] = nFileLength; @W8}N|jek
} DZRxp,
} l`&6W?C
c5e\ckqm^
[r8 d+
//启动子线程 MF}Lv1/[-J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?8@*q6~8
for(int i=0;i<nStartPos.length;i++) C4tl4df9
{ E{s|#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l|A8AuO*?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Mqp68%
nStartPos,nEndPos,i); xUi!|c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QJWES%m`
fileSplitterFetch.start(); [Z\1"m
} ?w/nZQWi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .~L4#V{c~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zI!R-Nb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (H+[^(3d2
nEndPos = " + nFileLength); ~4MjJKzA
// fileSplitterFetch[nPos.length-1].start(); m1i+{((
yQ{_\t1Wd
R"gm]SQ/
//等待子线程结束 P&0cF{
//int count = 0; X-#mv|3
//是否结束while循环 JK"uj%
boolean breakWhile = false; HF+fk*_Q
' u};z:t
sDm},=X}
while(!bStop) &6=ZT:.6Te
{ )]> '7] i
write_nPos(); b^DV9mO4J
Utility.sleep(500); ws>Iyw.u
breakWhile = true; }#>d2 =T$
x[W]?`W3r~
-#;VFSz,9*
for(int i=0;i<nStartPos.length;i++) ptyDv
{ H)T# R?
if(!fileSplitterFetch.bDownOver) o!r4 frP
{ BON""yIC
breakWhile = false; !9LAXM
break; ' 5 qL
} B4Af
} S aet";pf`
if(breakWhile) 6XL9 qb~X
break; >ha Ixs`9
efkie}
n3g WMC
//count++; UN?T}p- oF
//if(count>4) C%?D E@k
// siteStop(); Pq\V($gN
} Rn(F#tI
I+?$4SC
2mU-LQ1WN
System.err.println("文件下载结束！"); zGd*Q5l
} T.PZ}4
catch(Exception e){e.printStackTrace ();} |ezO@
} A;j$rGx
FJ,\?ooGf
*5'6E'
//获得文件长度 >\x_"oR
public long getFileSize() pD_eo6xX
{ 5`'au61/2
int nFileLength = -1; ?Gv!d
try{ `)!2E6 =
URL url = new URL(siteInfoBean.getSSiteURL()); +6)kX4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9 roth
httpConnection.setRequestProperty("User-Agent","NetFox"); j X!ftm2
UFAMbI
hPi :31-0
int responseCode=httpConnection.getResponseCode(); P}WhE
if(responseCode>=400) X`v79`g_
{ X1V}%@3:
processErrorCode(responseCode); MN M>
return -2; //-2 represent access is error ]#-/i2-K
} i2}=/
iLd"tn'
f+aS2k(e>
String sHeader; QRZTT qG
9Glfi@.
*ez~~ Y
for(int i=1;;i++) (=tF2YBV
{ >< _Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \ [^) WQ
//Utility.log(in.readLine()); ]V769B9
sHeader=httpConnection.getHeaderFieldKey(i); {9|$%4kRl
if(sHeader!=null) J(&M<<%
{ 0e:QuV2X
if(sHeader.equals("Content-Length")) iMeRQYW
{ 9s6>9hMb)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zmfRZ!Eh
break; %)hIpxOrX
} J%-lw{FC
} vH?+JN"A
else pT;-1c%:
break; &~JfDe9IS
} g*r{!:,t
} %f> |fs
catch(IOException e){e.printStackTrace ();} si!9Gz;
catch(Exception e){e.printStackTrace ();} >7(~'#x8A"
>&Ui*
-}qGb}F8!
Utility.log(nFileLength); {Fp`l\,
s8yTK2v2\
}!yD^:[5
return nFileLength; 0O['-x
} X6N]gD
d,J<SG&L&
kq}eUY]
//保存下载信息（文件指针位置） fF9oYOh|
private void write_nPos() E%2!C/+B
{ >]XaUQ-
try{ ND55`KT4
output = new DataOutputStream(new FileOutputStream(tmpFile)); o +QzQ+ Z
output.writeInt(nStartPos.length); : `6$/DK
for(int i=0;i<nStartPos.length;i++) id#k!*$7
{ G0;EbJ/&
// output.writeLong(nPos); WP@JrnxO\`
output.writeLong(fileSplitterFetch.nStartPos); <;,S"e
output.writeLong(fileSplitterFetch.nEndPos); Th;gps%b
} J.e8UQ@=5
output.close(); D@rn@N
} qvfAG 0p
catch(IOException e){e.printStackTrace ();} ekl?K~
catch(Exception e){e.printStackTrace ();} ({H+ y 9n
} o~.o^0Y
Puth8$
gcW{]0%L^
//读取保存的下载信息（文件指针位置） K@j^gF/0B
private void read_nPos() c]aK N
{ ;/)Mcx]n
try{ d0}%%T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DvRA2(M
int nCount = input.readInt(); _^xh1=Qr}n
nStartPos = new long[nCount]; |p8"9jN@}c
nEndPos = new long[nCount]; |!xfIR>=F
for(int i=0;i<nStartPos.length;i++) [`zbf_RyO
{ =S[FJaIu7
nStartPos = input.readLong(); 6Er0o{iI
nEndPos = input.readLong(); e2-70UvW^
} +Sdx8 Z5
input.close(); vA"`0
} ReB(T7Vk=
catch(IOException e){e.printStackTrace ();} 4Fr7jD,#k
catch(Exception e){e.printStackTrace ();} Q&.IlVB[
} iQm.]A
@^:7UI_
\Sq"3_m4T
private void processErrorCode(int nErrorCode) r_V2 J{B
{ ZXsY-5$#d-
System.err.println("Error Code : " + nErrorCode); JW%/^'
} =~W0~lxX
`r'0"V
S4{Mu(^xT
//停止文件下载 %];h|[ax]
public void siteStop() z7@(uIl=X
{ Ah"'hFY
bStop = true; ENYF0wW
for(int i=0;i<nStartPos.length;i++) 9#EHXgz
fileSplitterFetch.splitterStop(); ;5Wx$Yfx
_86*.3fQG
S-M)MCL
} !}L~@[v,uL
} aX[1H6&=7
//负责部分文件的抓取 x'=3&vc4
**FileSplitterFetch.java $xUzFLh=`
*/ MKVfy:g%So
package NetFox; )4'x7Qg/
M~ i+F0
Q2[prrk%j
import java.io.*; k binf
import java.net.*; :p\(y
/+x#V!zM
wzDk{4U
public class FileSplitterFetch extends Thread { 6HEqm>Yau
C`yvBt40r
'd2qa`H'}B
String sURL; //File URL =YXe1$ $
long nStartPos; //File Snippet Start Position j*eUF-J1
long nEndPos; //File Snippet End Position 4[LLnF--
int nThreadID; //Thread's ID ElEv(>G*
boolean bDownOver = false; //Downing is over ]M+VSU
boolean bStop = false; //Stop identical Z92iil;t
FileAccessI fileAccessI = null; //File Access interface :~ZqB\>i
eC+"mhB
QX/X {h6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *%OYAsc
{ ;LQ# *NjL\
this.sURL = sURL; l\T!)Ql
this.nStartPos = nStart; PkPDVv
this.nEndPos = nEnd; &*G5J7%w
nThreadID = id; d%#!nq{vd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m?D <{BQ;
} \uU=O )
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LC,*H0
public void run() V9fGVDl;
{ ;0w^ud
while(nStartPos < nEndPos && !bStop) <fC@KY>#
{ S' (cqO}=F
Hhe{+W@~
yyY~ *Le
try{ lC'{QUC
URL url = new URL(sURL); u0bfX,e2U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *PSvHXNi
httpConnection.setRequestProperty("User-Agent","NetFox"); V-KL%
String sProperty = "bytes="+nStartPos+"-"; bH\'uaJ
httpConnection.setRequestProperty("RANGE",sProperty); vU_d=T%$
Utility.log(sProperty); (~j,mk
T~i%j@Q.6
w24{_ N
InputStream input = httpConnection.getInputStream(); zb>f;[
//logResponseHead(httpConnection); aN^]bs?R
[%j?.N
?a'6EAErC
byte[] b = new byte[1024]; >63)z I
int nRead; <*s"e)XeqF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^[{`q9A#d
{ Q0zW ]a
nStartPos += fileAccessI.write(b,0,nRead); {fGd:2dh
//if(nThreadID == 1) Usa+b A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jOUK]>ox:
} csH2_+uG
?muDTD%c
<Rcu%&;i
Utility.log("Thread " + nThreadID + " is over!"); [[R7~.;
bDownOver = true; !dU9sB2
//nPos = fileAccessI.write (b,0,nRead); ;y>S7n>n:
} o"rq/\ovv
catch(Exception e){e.printStackTrace ();} Ds%9cp*6
} ~Cjz29|gp
} "w}-?:# j
X+=-f^)&
Nls83 W
//打印回应的头信息 8YuJ8KC
public void logResponseHead(HttpURLConnection con) -PNi^ K_
{ )y9;OA
for(int i=1;;i++) Y/.AUN Z
{ &+mV7o
String header=con.getHeaderFieldKey(i); A/q2g7My
if(header!=null) ifXW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !M
Utility.log(header+" : "+con.getHeaderField(header)); KcC!N{
else %'Zc2h&z
break; ,N53Iic
} &4,WG
} ?Bo?JMV
OFc\fW#
ojHhT\M`
public void splitterStop() !Y (apVQ
{ t#C,VwMe[
bStop = true; >\V6+$cNp
} ]UDd :2yt
q[7CPE0n
9<yAQ?7L
} \+-zRR0
+'%@!
bS>R5*Zp
/* HF"Eys
**FileAccess.java ~12_D'8D[
*//文件访问(定位，写) "`pNH'
package NetFox; S]}}A
import java.io.*; n.*3,4.]
\tY"BC4.
{Fbg]'FQ
public class FileAccessI implements Serializable{ u*2fP]n
kw*)/$5]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P0^c?s"I
RandomAccessFile oSavedFile; 8{dEpV*
long nPos; /Rj#sxtdw
}g~g50ci
3y99O $EAc
public FileAccessI() throws IOException KU-'+k2s;p
{ 11@]d]v ,
this("",0); Q]@c&*_|
} Fh K&@@_
z v>Oh#
>OV<_(S4
public FileAccessI(String sName,long nPos) throws IOException nX|Q~x]
{ H@GE)I>^@
oSavedFile = new RandomAccessFile(sName,"rw"); NUCiY\td
this.nPos = nPos; )l&D]3$6K
oSavedFile.seek(nPos); #%:c0=
} 2-~|Z=eGW
F/>*Ifs
|( G2K'Ab
public synchronized int write(byte[] b,int nStart,int nLen) vA=Z=8
{ yGxv?%%2
int n = -1; (&jW}1D
try{ kY"KD22a
oSavedFile.write(b,nStart,nLen); @Br {!#Wf
n = nLen; #)o7"PW:
} #uSK#>H_!
catch(IOException e) .wmnnvtl,
{ wd[eJcQ,
e.printStackTrace (); ks*Y9D*=
} q*,Q5
uRE*%d>
)P?IqSEA%
return n; re^Hc(8M
} !^e =P%S
'cV?i&;
yhpz5[AuO
} rEdY>\'
/.Fj.6U5
_%~$'Hy
/* 54{q.I@n
**SiteInfoBean.java +`B'r '
*/ $IVwA
package NetFox; "X04mQn15
8Hi!kc;f6>
^rL_C}YBj-
public class SiteInfoBean { /)EY2Y'
EF#QH _X
87V1#U^
private String sSiteURL; //Site's URL UL( lf}M
private String sFilePath; //Saved File's Path {hQ6K)s
private String sFileName; //Saved File's Name I9Eu',
private int nSplitter; //Count of Splited Downloading File Kc #|Z
ecj7BT[mLI
Dzl;-]S
public SiteInfoBean() N2ied^* 0
{//nSplitter的缺省值为5 MV0Lq:# N
//default value of nSplitter is 5 +pf5\#l?
this("","","",5); 6?qDdVR~]
} x({H{'9?
9Ma0^_
rv>^TR*,!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BQ/PGY>
{ gd7^3q[$h
sSiteURL= sURL; hIYTe
sFilePath = sPath; }^-<k0A4?
sFileName = sName; 8 TiG3
this.nSplitter = nSpiltter; P:C2G(V1AR
w8Vw1wW
bc I']WgB-
} HpVjee
t\4[``t
D\1k.tI
public String getSSiteURL() >\2:\wI
{ kL>d"w
return sSiteURL; @F~LW6K
} x;LzG t:w
?+0GfIV
At6qtoPRA
public void setSSiteURL(String value) >?lOE -}^
{ qQ0C?
sSiteURL = value; uuNR?1fS
} kW@,$_cK
w%y\dIeI'
?F7o!B
public String getSFilePath() C/=XuKE-t
{ yClx` S(
return sFilePath; +Qxu$#
} 71fk.16
d$W
-%CoWcGP
public void setSFilePath(String value) (:pq77
{ 5fJ[}~
sFilePath = value; EH*o"N`!r
} UPiW73Nu
,=QM#l]
b'YE9E
public String getSFileName() b:J(b?
{ MZ>6o5K|
return sFileName; p(F" /
} /9pM>Cd*Z
$((6=39s
(ljF{)Ml+=
public void setSFileName(String value) ])DX%$f
{ _>m-AI4^
sFileName = value; 44ed79ly0)
} q.#[TI ^
ccFn.($p?,
.w?(NZ2~
public int getNSplitter() @}-r&/#
{ ->^~KVh&
return nSplitter; N|g;W
} )~J>X{hy
kq=V4-a[
FQz?3w&ia
public void setNSplitter(int nCount) a:,y Z
{ ;`YkMS`=W
nSplitter = nCount; ;%C'FV e]
} v``-F(i$
} )E#2J$TD
=sJ _yq0#R
[,RI-#n
/* }[+!$#
**Utility.java j@gMbiu
*/ >'uU)Y{
package NetFox; I04jjr:<
cF)/^5Z
B+d<F[|
public class Utility { F>je4S;
|{r$jZeE
j%u-dr
public Utility() N,dT3we
{ M 3 '$[
f/,>%j=Ms
_@mRb^
} l>gI&1)%
xT&(n/
//线程睡眠 2T@GA1G
public static void sleep(int nSecond) kd`0E-QU
{ D_mL,w
try{ 7?8wyk|x
Thread.sleep(nSecond); {5r0v#;
} >T2LEW
catch(Exception e) E/&Rb*3
{ u%/fx~t$
e.printStackTrace (); H=*5ASc
} im} ?rY
} {Gq*e/
<ljI;xE
//日志 %CwL:.|
public static void log(String sMsg) n% 'tKU\q
{ Pi,QHb`>
System.err.println(sMsg); ml0.$z
} v2r&('pV
UJfT!==U
>d"3<S ;b
public static void log(int sMsg) n\Fp[9+Z\
{ &AVpLf:?
System.err.println(sMsg); {t"+ 3zy'
} Oa;X+
} EN{]Qb06A
!Cgx.
" 96yp4v@
/* %*aJLn+]_R
**TestMethod.java ^,l_{
*/ ?Xdak|?i
package NetFox; 9Zry]$0~R
NN0$}acp
Uoya3#4 G
public class TestMethod { [ EFMu;q
iovfo2!hD
09A X-JP
public TestMethod() "mL++>ZSQ
{ ///xx/weblogic60b2_win.exe c4&'D;=
try{ 73{'kK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q9}dHIe1E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `Y-|H;z
SiteFileFetch fileFetch = new SiteFileFetch(bean); $aHAv/&(5
fileFetch.start(); I;5R2" 3
} 8[r9HC
catch(Exception e){e.printStackTrace ();} )jWOP,|
(,^*So/
>hBxY]< \
} x!\ONF5$
oH0X<'
43?^7_l-
public static void main(String[] args) _&K
{ |KB0P@=a
new TestMethod(); :m86 hBE.
} D=:04V}2+
} !D!~^\
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