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)); <B8!.|19
} 0b(N^$js'
for(int i=0;i<nEndPos.length-1;i++) fkNbS
{ e'D&8z_;
nEndPos = nStartPos[i+1]; I"7u2"@-8j
} O/(xj2~$J
nEndPos[nEndPos.length-1] = nFileLength; vTw>JNVI
} GYUn6P
} yd`mG{Z
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RQu(Wu|m.
//启动子线程 $[=%R`~w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,]c 1A$Sr0
for(int i=0;i<nStartPos.length;i++) 3 xp)a%=7
{ !H>R%g#28_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M?uC%x+S$_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xAMW-eF?d
nStartPos,nEndPos,i); AX/m25x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w!clI8v/
fileSplitterFetch.start(); ZSd4z:/
} PdtvU-(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,^f+^^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $aXer:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U2s /2 [.
nEndPos = " + nFileLength); G,Azm}+
// fileSplitterFetch[nPos.length-1].start(); I,@6J(9
>>fH{/l
*N'p~LJ
//等待子线程结束 "d5n \@[t
//int count = 0; OMg<V
//是否结束while循环 ?zHPJLv|Y
boolean breakWhile = false; L<{i,'M
ThbGQ"/
zi*R`;_`,
while(!bStop) pOG1jI5<{8
{ 2'MZ s]??w
write_nPos(); m#Z# .j_2
Utility.sleep(500); Is?La
breakWhile = true; 9ahWIO%
j+v=Ul|l
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for(int i=0;i<nStartPos.length;i++) L"*/:$EJL.
{ O~K>4ax
if(!fileSplitterFetch.bDownOver) gi _5?$
{ ` 3K)GA
breakWhile = false; O2dW6bt
break; )*x6 FfTUd
} u-G+ j)
} Jd^,]
if(breakWhile) uT7B#b7
break; gz#i.-
q2:6QM&
eHNyNVz
//count++; \%N!5>cZ{
//if(count>4) 6-B|Y3)B
// siteStop(); ):_\;.L
} Ur=(.%@
R)ITy!z
b-Q>({=i
System.err.println("文件下载结束！"); !.(P~j][
} T&o(N3lW
catch(Exception e){e.printStackTrace ();} VYImI>.t{
} Ob`d
!AfHk|
s?,Ek
//获得文件长度 Opc ZU{4b
public long getFileSize() JB]q
{ iaE^a^*
int nFileLength = -1; H{?vbqQ
try{ "J8vjr1/
URL url = new URL(siteInfoBean.getSSiteURL()); 0Bi.6r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e5*hE
httpConnection.setRequestProperty("User-Agent","NetFox"); rJbf_]^
=\wxsL
>!bJslWA
int responseCode=httpConnection.getResponseCode(); @{tz:f
if(responseCode>=400) 8~z~_TD6m@
{ 3!oi+_
processErrorCode(responseCode); dD|OSB7I7
return -2; //-2 represent access is error NmJWU:W_@
} hD*SpVIU
YhE+W
LKOwxF#TKT
String sHeader; P0j8- I
p(`6hWx
(w/T-*
for(int i=1;;i++) B s#hr3h-
{ .|b$NM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K<ft2anY5
//Utility.log(in.readLine()); +kO!Xc%P&
sHeader=httpConnection.getHeaderFieldKey(i); (UvM@]B
if(sHeader!=null) q[W 0 N>
{ Q&=w_Wc
if(sHeader.equals("Content-Length")) jun_QiU:2
{ _Wq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cacr=iX
break; %'7lbpy,f
} J1sv[$9
} hp7|m0.JW
else ?6un4EVL{
break; UK O[r;
} ^!ZC?h!rG
} YS@ypzc/
catch(IOException e){e.printStackTrace ();} J1I ;Jgql(
catch(Exception e){e.printStackTrace ();} ERE)A-8
^N;.cY
TNY&asQo
Utility.log(nFileLength); s ;oQS5Y
1o;J,dYu
xLWwYK
return nFileLength; $oU*9}}Rn
} b TM{l.Aq3
%GA"GYL9'
evAMJ=
//保存下载信息（文件指针位置） -Rd/Gx
private void write_nPos() #_J@-f7^
{ pg.ri64H<
try{ UT=tT)4b
output = new DataOutputStream(new FileOutputStream(tmpFile)); F{Jw^\
output.writeInt(nStartPos.length); NOiN^::m
for(int i=0;i<nStartPos.length;i++) ,p2s:&"
{ !K}~/9Z=m
// output.writeLong(nPos); (ehK?6[
output.writeLong(fileSplitterFetch.nStartPos); `W:%mJd9
output.writeLong(fileSplitterFetch.nEndPos); ?:8ido#-
} +*T7@1
output.close(); Dhw(#{N
} ;q:zT\A
catch(IOException e){e.printStackTrace ();} $M lW4&a|
catch(Exception e){e.printStackTrace ();} Ax?y
} O%(fx!c`
kabnVVn~
uK$9Ll{lk
//读取保存的下载信息（文件指针位置） q[`]D7W "
private void read_nPos() !tMuuK?IL=
{ BJB^m|b)
try{ D2!X?"[P
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UAFwi%@!-q
int nCount = input.readInt(); x:>wUhzZ
nStartPos = new long[nCount]; E^lvbLh'
nEndPos = new long[nCount]; Wm"4Ae:B
for(int i=0;i<nStartPos.length;i++) + SFVv_n
{ gp^5#
nStartPos = input.readLong(); d + /&?3
nEndPos = input.readLong(); %?uc><&?e
} ;WM"cJo9
input.close(); {VvqO7A
} cU@SIJ)
catch(IOException e){e.printStackTrace ();} [}/LD3
catch(Exception e){e.printStackTrace ();} u7\J\r4,+
} i2YuOV!
Q}K#'Og
{QZUDPPR
private void processErrorCode(int nErrorCode) *4xat:@{{
{ SHbtWq}T
System.err.println("Error Code : " + nErrorCode); ~\.w^*$#Y
} ^3{TZ=_;|
OK6]e3UO
;04Ldb1{|3
//停止文件下载 e8]\U/
public void siteStop() 8V)^R(\;
{ r>"
bStop = true; RGg(%.
for(int i=0;i<nStartPos.length;i++) n'01Hh`0
fileSplitterFetch.splitterStop(); oA7;.:3
V7[zAq
"@d[h,TM
} wsN?[=l{s
} x&9hI
//负责部分文件的抓取 C\nhqkn
**FileSplitterFetch.java fX.>9H[w@~
*/ 4%}*&nsI-Z
package NetFox; ZF|+W?0&%
>`wV1^M6?
lR[qqFR
import java.io.*; 'u_t<F]b
import java.net.*; Ikiib WQL+
T/xp?Vq6/
2 :mn</z
public class FileSplitterFetch extends Thread { I8<,U!$
\B 0ywN?
2Sp=rI
String sURL; //File URL CkD#/
long nStartPos; //File Snippet Start Position ;SaX;!`39+
long nEndPos; //File Snippet End Position C;`XlQG `
int nThreadID; //Thread's ID Bj}^\Pc;}
boolean bDownOver = false; //Downing is over {>,V\J0p
boolean bStop = false; //Stop identical !V\Q<So<
FileAccessI fileAccessI = null; //File Access interface \XM^oE#G
ZAUQJS 91E
&S]@Ot<z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F;[T#N:~
{ w@c87;c
this.sURL = sURL; |- rI@2`
this.nStartPos = nStart; rEv*)W
this.nEndPos = nEnd; r8&^>4
nThreadID = id; OD 3f.fT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E3l> 3
} :.d:9Z|_
\&3"<6xA
^;maotHn
public void run() J.dLPKU;-
{ t|!j2<e
while(nStartPos < nEndPos && !bStop) E)7F\w
{ S:q3QgU=X
CQr<N w
.E&z$N
try{ FwY&/\J7V
URL url = new URL(sURL); f<*Js)k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]M[#.EX
httpConnection.setRequestProperty("User-Agent","NetFox"); I}t3 p|z
String sProperty = "bytes="+nStartPos+"-"; A"l?:?rtw]
httpConnection.setRequestProperty("RANGE",sProperty); r"a5(Q;n
Utility.log(sProperty); dT$M y`>
qY$qaM^=
Fxqp-}:
InputStream input = httpConnection.getInputStream(); n?ctLbg
//logResponseHead(httpConnection); ~$f;U
E55t*^`
UH>F|3"d
byte[] b = new byte[1024]; D?,#aB"
int nRead; M$d%p6Cv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xD /9F18
{ RZ7(J
nStartPos += fileAccessI.write(b,0,nRead); .tmiQ.
//if(nThreadID == 1) N!x =eC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "zY](P
} ND,Kldji
zBp{K@U[|M
{}m PEd b
Utility.log("Thread " + nThreadID + " is over!"); nG,U>)
bDownOver = true; >Clh] ;K
//nPos = fileAccessI.write (b,0,nRead); +|{RE.DL
} f%)zg(YlO
catch(Exception e){e.printStackTrace ();} $GQ-(/
} ;k86"W
} za9)Q=6FD
rVa?JvDO=
6ubL1K
//打印回应的头信息 fr}Eaa-{^
public void logResponseHead(HttpURLConnection con) X_G| hx
{ >'5_Y]h4m|
for(int i=1;;i++) :BukUket1e
{ he-Ji
String header=con.getHeaderFieldKey(i); JwRF(1_sM
if(header!=null) eo!zW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GK}'R=
Utility.log(header+" : "+con.getHeaderField(header)); 9F- )r'
else 'snn~{hG
break; 5,;`$'?a%
} G"59cv8z4R
} a7/-wk
\WrFqm#
lvpc*d|K
public void splitterStop() X$\i{p9jw
{ KZe)K_1[
bStop = true; `L5~mb;7*
} J3b4cxm
@[?!s%*2
nGf);U#K
} &Q=ZwC7#
omf Rs
]:$ O{y
/* L~/qGDXC?
**FileAccess.java qxMnp}O
*//文件访问(定位，写) >x@P|\
package NetFox; c<BO gNr
import java.io.*; XC3Kh^
'[(nmx'yVJ
}o,z!_^PLQ
public class FileAccessI implements Serializable{ +P`(Rf"luu
\#x}q'BC4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E%TpJl'U
RandomAccessFile oSavedFile; 9>#:/g/
long nPos; x/MZ(A%D
^D_/=4rz8
6V+ qnUk
public FileAccessI() throws IOException &>jAe_{",
{ ]43bere
this("",0); (5Tvsw`
} V'2EPYB
+1Ph<zq"
l n}}5Q
public FileAccessI(String sName,long nPos) throws IOException "%QD{z_L
{ m:O(+Fl
oSavedFile = new RandomAccessFile(sName,"rw"); y8bM<e2 U
this.nPos = nPos; OAZ#|U
oSavedFile.seek(nPos); Pe~`16f
} k)FmDX
&?p:3%;Dr
|"$uRV=qm
public synchronized int write(byte[] b,int nStart,int nLen) 0-3rQ~u
{ ?vGffMm
int n = -1; 5lJ)(|_
try{ ?68uS;
oSavedFile.write(b,nStart,nLen); :Ze+%d=
n = nLen; :y,v&Kk#T
} d(*fy}
catch(IOException e) W {.78Zi9K
{ td-3h,\\
e.printStackTrace (); ? {F{;r
} -,":5V26
]y)Q!J )Q
baoD(0d
return n; N 6O8Wn
} dd7 =)XT+
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qJT0Y/l:(
} ]&i+!$N_
[{<dbW\ 9
6a>H|"PNE
/* E)t
**SiteInfoBean.java 4R) |->"
*/ 6j8<Q 2
package NetFox; jUjr6b"
!m{2WW-
9-bG<`v\E
public class SiteInfoBean { Lg`Jp&Kg
, Ut Hc]
cf[vf!vi
private String sSiteURL; //Site's URL r<L#q)]
private String sFilePath; //Saved File's Path 3@O0^v-
private String sFileName; //Saved File's Name ?Zyok]s
private int nSplitter; //Count of Splited Downloading File gw3NS8 A+
JK~ m(oQ
P-JfV7(O8
public SiteInfoBean() $ A-b vL
{//nSplitter的缺省值为5 F}rPY:
//default value of nSplitter is 5 HrqF![_
this("","","",5); ._p""'Sa
} \w)?SVp
76#.F
*"G8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {%']w
{ d\XRUO[
sSiteURL= sURL; i&@,5/'-_O
sFilePath = sPath; ^ZQCIS-R
sFileName = sName; LEc8NQs
this.nSplitter = nSpiltter; DQ=N1pft2v
A@$fb}CF
s5Fr)q// !
} FyEDt@J
%N~CvN@T
VVrwOoCN
public String getSSiteURL() iM64,wnA
{ .:;fAJPf
return sSiteURL; `.k5v7!o
} 5&4F,v[zp
yCM{M
<~%t$:
public void setSSiteURL(String value) zw:/!MS
{ \kwe51MQ
sSiteURL = value; +|nsu4t,<
} gB CC
{>.>7{7
S+*cbA{J|
public String getSFilePath() ;x>;jS.t
{ T=? bdIl
return sFilePath; .{N\<01
} )Ul&1UYA
yer> x
.g-3e"@
public void setSFilePath(String value) uU+s!C9r
{ O=O(3Pf>
sFilePath = value; -"Gl 4)
} L/k40cEI^z
tmxPOe
BpXEK.Xw
public String getSFileName() HRRngk#lV
{ f0F#Yi{fw
return sFileName; VA]ZR+m
} _XN~@5elrC
F|]rA*2u
9c5!\m1
public void setSFileName(String value) >1XL;)IL>
{ dx359
sFileName = value; x9*ys;~w
} g@(30{
CB@B.)E
|,fh)vO
public int getNSplitter() x[m'FsR4
{ T^.{9F]*S
return nSplitter; $wXih#7
} rAatJc"0
S1>Z6
WRMz]|+}4
public void setNSplitter(int nCount) WB"$u2{|i
{ j];1"50?
nSplitter = nCount; |\p5mh
} anitqy#E
} xXa#J)'
#HcI4j:s!
)9pBu B
/* Y_shy6"KH
**Utility.java }I<N^j=/pO
*/ H5^Y->
package NetFox; & 3I7]Wm
sRil>6QR
i0&) N,5_
public class Utility { 6(5c7R#
}`@?X"r
ks^|>
public Utility() 0- Yeu5A
{ $pBr &,
3V!x?H$
>huqt|S*9
} { ;' :h
pqd4iR Wv
//线程睡眠 1'OD3~[R
public static void sleep(int nSecond) B$EK_@M
{ IHfSkFz`j
try{ )ldUayJ
Thread.sleep(nSecond); r?XDvU
} C_89YFn+
catch(Exception e) 8ok7|DJ
{ z5I^0'
e.printStackTrace (); Lj-{t% }
} $ACe\R/%
} 8|_K
dTgM"k
//日志 6 cr^<]v!
public static void log(String sMsg) Uc>LFX& -B
{ o[H\{a>
System.err.println(sMsg); |<2JQ[]
} iqlVlm>E
vD"_X"v
nvwDx*[qN
public static void log(int sMsg) J4&XPr9
{ 8Y]}Gb!
System.err.println(sMsg); BfEx'C
} k4*! Q_A
} n+S&!PB
%`N&ti
iPJ9Gh7
/* ^$?7H>=_ha
**TestMethod.java >R) F}
*/ gtl;P_
package NetFox; aSxG|OkKy
Ny[s+2?
(#lm#?<)
public class TestMethod { fLc!Sn.Y
V4qZc0<,H
T=Ol`?5
public TestMethod() 2@OBeR
{ ///xx/weblogic60b2_win.exe `,Q<YT ~
try{ ] +sSg=N7i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >dcqPNDg1^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1_XO3P\
SiteFileFetch fileFetch = new SiteFileFetch(bean); nN!vgn j
fileFetch.start(); la1D2 lM
} MH2OqiCI
catch(Exception e){e.printStackTrace ();} <m:4g ,6
{m>~`
sL;z"N@PK
} SIJ# ?0,
V&$ J;
t PAt?
public static void main(String[] args) Fj36K6!#?
{ 'XG:1Bpm
new TestMethod(); h7)VJY
} 6Eij>{v
} `mQP{od?"?
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