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)); j&T/.]dX&
} Vg \-^$
for(int i=0;i<nEndPos.length-1;i++) a _
{ ~iwEhF
nEndPos = nStartPos[i+1]; AF3t#)q
} JEHV\=
nEndPos[nEndPos.length-1] = nFileLength; zZ32K@
} oN `tZ;a
} #mkr]K8A4
w,}}mC)\*
n"FOCcTIs
//启动子线程 7vj[ AOq3l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f6|3| +
for(int i=0;i<nStartPos.length;i++) iU%Gvf^?'5
{ =l7LEkR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sM5 w~R>Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^G2vA8%
nStartPos,nEndPos,i); r]HLO'<]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !%s7I^f*
fileSplitterFetch.start(); "apv)xdW
} Qgx~'9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TJ;v}HSo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $\^]MxI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V'mpl
nEndPos = " + nFileLength); 2{V|
// fileSplitterFetch[nPos.length-1].start(); e#nTp b
3&y u
=]zPUzr,|
//等待子线程结束 --^D)n
//int count = 0; b%PVF&C9W
//是否结束while循环 }?fa+FQGp
boolean breakWhile = false; J$EEpL
KFfwZkj{
vq5I 2
while(!bStop) <M&]*|q>g%
{ 6wu/6DO
write_nPos(); ]@8=e'V
Utility.sleep(500); hYWWvJ)S
breakWhile = true; %[Ds-my2
I^ >zr.zA
&9ZIf#R
for(int i=0;i<nStartPos.length;i++) H~G=0_S
{ ^@19cU?q
if(!fileSplitterFetch.bDownOver) =OHDp7GXO>
{ d.}rn"(z
breakWhile = false; ^|K*lI/
break; S}< <jI-z
} #TSM#Uqe
} C,<TAm
if(breakWhile) _:K}DU'6
break; jU#%@d6!#
7J;.T%4l
=f|>7m.p
//count++; ]_pL79y
//if(count>4) 7>~iS@7GV
// siteStop(); 5:PZ=jPR
} 8/F2V?iT
R|M:6]}
nWl0R=
System.err.println("文件下载结束！"); $U0(%lIU
} uf>w*[m5
catch(Exception e){e.printStackTrace ();} @'rO=(-b
} Ucy9fM
;C{_T:LS
'9[_w$~(
//获得文件长度 y]+A7|
public long getFileSize() /vV 0$vg
{ .Lp-'!i
int nFileLength = -1; 8)tyn'~i
try{ .cabw+&7
URL url = new URL(siteInfoBean.getSSiteURL()); b;O+QRa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8&;dR
httpConnection.setRequestProperty("User-Agent","NetFox"); co@8w!W
lz*2wGI9
@t^2/H ?O
int responseCode=httpConnection.getResponseCode(); <|_Ey)1 6
if(responseCode>=400) %51pfuL
{ >I!(CM":s$
processErrorCode(responseCode); Uy_=#&jg
return -2; //-2 represent access is error 2~4C5@SxL
} gJ7$G3&oZg
y5ExEXa
<?g{Rn
String sHeader; C,]Ec2
GGuLxc?(
z?aDOh
for(int i=1;;i++) @gj5'
{ (BGipX4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w}i.$Qt
//Utility.log(in.readLine()); ={Hbx>p
sHeader=httpConnection.getHeaderFieldKey(i); P}I*SV0
if(sHeader!=null) [KKoEZ
{ `Qhh{
if(sHeader.equals("Content-Length")) p(8\w-6
{ :Rn9rdX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xle29:?l
break; wf4Q}l2,d
} F)IP~BE-k
} Uoe?5Of(*
else A^7!+1*K+
break; b2Hpuej
} d]^i1
} AK!G#ug
catch(IOException e){e.printStackTrace ();} S=2,jPX2r
catch(Exception e){e.printStackTrace ();} 0#7dm9
ex1ecPpN
L}mhMxOTi
Utility.log(nFileLength); x9e 9$ww}
#?*jdN:
P:vy
return nFileLength; <b\urtoJ
} MI}D%n*
6>Cubb>
t|m3b~Oyv
//保存下载信息（文件指针位置） $3ILVT
private void write_nPos() Vh8uE
{ 5-*]PAC
try{ [ n2udV
output = new DataOutputStream(new FileOutputStream(tmpFile)); \);rOqh
output.writeInt(nStartPos.length); ?1uAY.~ZZB
for(int i=0;i<nStartPos.length;i++) 2~<0<^j/]
{ _biJch
// output.writeLong(nPos); #L)rz u
output.writeLong(fileSplitterFetch.nStartPos); LcXMOT)s
output.writeLong(fileSplitterFetch.nEndPos); 'w2;oO
} Z:_y,( 1Q
output.close(); ?zEF?LJoK
} 2YyZiOMSc
catch(IOException e){e.printStackTrace ();} d#\n)eGr
catch(Exception e){e.printStackTrace ();} :9b RuUm
} >g&`g}xZQ
qHCs{ u
_+En%p.m
//读取保存的下载信息（文件指针位置） )R4<* /C:w
private void read_nPos() Nt8(
{ "x)DE,
try{ .vO.g/o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y"qY@`
int nCount = input.readInt(); |@BN+o;`Om
nStartPos = new long[nCount]; tp<VOUa
nEndPos = new long[nCount]; [P/gM3*'
for(int i=0;i<nStartPos.length;i++) &; \v_5N6
{ v,&2!Zv
nStartPos = input.readLong(); ho1F8TG=
nEndPos = input.readLong(); b5Pn|5AVj
} d%3BJ+J
input.close(); Ie"R,,c
} L ~w=O!
catch(IOException e){e.printStackTrace ();} 6{'6_4;Fv(
catch(Exception e){e.printStackTrace ();} ^|C|=q~:
} F0Hbklr
B]7jg9/
Kxn7sL$]=F
private void processErrorCode(int nErrorCode) N6;Z\\&0^q
{ 7&4,',0VL
System.err.println("Error Code : " + nErrorCode); L|LTsRIq
} :!$z1u8R
">3@<f>
,X^_w g
//停止文件下载 Zi)b<tM q
public void siteStop() 919g5f`
{ QGd- 9UEA]
bStop = true; =f!M=D
for(int i=0;i<nStartPos.length;i++) ]aNnY?qW5
fileSplitterFetch.splitterStop(); nY)Pxahm7
`Tj}4f
R6;>RRU_
} F]YKYF'1I
} t5h_Q92N
//负责部分文件的抓取 Z<W6Avr
**FileSplitterFetch.java E6:p
*/ ^A`(
package NetFox; ItADO'M
l #Q`f.
d&`j8O
import java.io.*; jm\#($gl=
import java.net.*; Wi^rnr'Ss
I?>T"nV +'
$sZHApJV+
public class FileSplitterFetch extends Thread { *a!!(cZZ
$0T"YC%
2(Uz9!<V
String sURL; //File URL 2-aYqMmT;
long nStartPos; //File Snippet Start Position sv"mba.J
long nEndPos; //File Snippet End Position I})t
int nThreadID; //Thread's ID #~;8#!X
boolean bDownOver = false; //Downing is over 2<Bv=B
boolean bStop = false; //Stop identical @88i/ Z_
FileAccessI fileAccessI = null; //File Access interface vv/,Rgv
^z^e*<{WEl
I!gj;a?R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X vMG09
{ PU5mz.&0'
this.sURL = sURL; ]0 RXo3
this.nStartPos = nStart; Hs=N0Sk]j
this.nEndPos = nEnd; tr8Cx~<
nThreadID = id; 4iqmi<[("
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z4ioXl
} Y&+_p$13
v&2@<I>
SzX~;pFM0
public void run() *`Xx_
{ /v4S@SQ+
while(nStartPos < nEndPos && !bStop) yB%)D0
{ <0)ud)~u
'-33iG
?i2Wst
try{ 0WE1}.J<
URL url = new URL(sURL); ^alZ\!B8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h6y4Ii
httpConnection.setRequestProperty("User-Agent","NetFox"); 8zDH<Gb
String sProperty = "bytes="+nStartPos+"-"; o MkY#<Q}
httpConnection.setRequestProperty("RANGE",sProperty); ~h0BT(p/
Utility.log(sProperty); ([b!$o<v
f~nt!$
zK4 8vo
InputStream input = httpConnection.getInputStream(); u#WTh%/
//logResponseHead(httpConnection); /I'u/{KB
`(/saq*
e>9Z:vY
byte[] b = new byte[1024]; =4<S8Cp
int nRead; \K~fRUo]=c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1]Q2qs
{ #0hNk%X=
nStartPos += fileAccessI.write(b,0,nRead); ]/Yy-T#@
//if(nThreadID == 1) OP`Jc$|6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'z}M[h K]
} 68<Z\WP
=yX&p:-&
igBrmaY'
Utility.log("Thread " + nThreadID + " is over!"); G].__]
bDownOver = true; $n Sh[{
//nPos = fileAccessI.write (b,0,nRead); 3*$9G)Ey
} _T|H69 J
catch(Exception e){e.printStackTrace ();} E\~ KVn
} RE $3| z
} 8+ F}`lLA
D`:d'ow~KQ
6$s0-{^
//打印回应的头信息 H9VXsFTW
public void logResponseHead(HttpURLConnection con) |\|)j>[i
{ ``|RO[+2
for(int i=1;;i++) dMs||&|&
{ ^qGA!_
String header=con.getHeaderFieldKey(i); X";ZUp
if(header!=null) 15KV}){
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wp%FM
Utility.log(header+" : "+con.getHeaderField(header)); wK'!xH^
else $dh4T";
break; *Ht*)l?
} c|}K_~l_
} 0w(T^GhZ
[AZaT
q@!'R{fu
public void splitterStop() Afy .3T @)
{ n5+S"
bStop = true; 4Kn9*V
} 7ec0Xh1
p/k<wCm6
mw(c[.*%
} /pN'K5@
A,-V$[;~D
~z K@pFeH
/* m io1kDq<
**FileAccess.java =^Sw*[eiy
*//文件访问(定位，写) Bhu@2KdA
package NetFox; w;c#drY7S
import java.io.*; E {KS a
1<a@p}
b-BM"~N'
public class FileAccessI implements Serializable{ p2x1xv
$xA J9_2P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~llMrl7
RandomAccessFile oSavedFile; ~|'y+h89
long nPos; uKbHFF
b H"}w$!>r
f `y" a@
public FileAccessI() throws IOException $89ea*k
{ sB( `[5I
this("",0); &IRA=nJ
} ZUXse1,
s~LZOPN
Z .bit_(
public FileAccessI(String sName,long nPos) throws IOException >v1 y0zx
{ }KA-t}8
oSavedFile = new RandomAccessFile(sName,"rw"); 0L:V#y-*
this.nPos = nPos; F)/~p&H
oSavedFile.seek(nPos); \f/#<|Hm
} *H5PT
CZJHE>
z1f^p7$M?
public synchronized int write(byte[] b,int nStart,int nLen) |^Ew<
{ }PI35i1!t
int n = -1; LG=X)w)W4S
try{ \5'O.*pr
oSavedFile.write(b,nStart,nLen); %j*k
n = nLen; V$dJmKg
} \Pl,' 1%
catch(IOException e) }XCR+uAz
{ lf%b0na?r
e.printStackTrace (); >f\zCT%cf
} |66m` <
fJLf7+q
K85_>C%g
return n; Z|ZBKcmg
} XogvtK*
wJ+U[a
2{t)DUs
} (Sth:{;
uxa=KM1H
J>=1dCK
/* k42b:W5%
**SiteInfoBean.java 908ayfVI
*/ e'1 ^+*bU
package NetFox; Y*@|My`
5v|H<wPp
})20Zld}a
public class SiteInfoBean { &/](HLdF
iV?` i
8[{|xh(
private String sSiteURL; //Site's URL !2}rtDE
private String sFilePath; //Saved File's Path g4N%PV8
private String sFileName; //Saved File's Name jHAWK9fa
private int nSplitter; //Count of Splited Downloading File s$DGd T)
\ Y*h
},DyU
public SiteInfoBean() n{dP@_>WS
{//nSplitter的缺省值为5 [ULwzjss#L
//default value of nSplitter is 5 4~O6$;!|~
this("","","",5); Zc-#;/b3T
} "r8EC
CI,lkO|C
K`hz t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TdQ]G2
{ :T_'n,
sSiteURL= sURL; j]pohxn$5
sFilePath = sPath; .Y!;xB/
sFileName = sName; ~|&="K4,:
this.nSplitter = nSpiltter; 0Tcz[$?
2;:lK":
{Q)dU-\
} CN7k?JO<
Q0pzW:=s]
#G3` p!"
public String getSSiteURL() kg<P t >
{ ^8:VWJM
return sSiteURL; ql^g~b
} hG=k1T%=
eSl]8BX_
?VB#GJ0M9
public void setSSiteURL(String value) eGLO!DdxZ
{ rO0ZtC{K
sSiteURL = value; 'WK;$XQ
} ;a|`s
=H[\%O~?b
[s~JceUyX
public String getSFilePath() )ZGYhE
{ wW-Ab
return sFilePath; *=Doe2(!C
} :$=|7v
- %|P
}sv!=^}BY3
public void setSFilePath(String value) ejVdxVr\7
{ 5MxH)~VQoM
sFilePath = value; WSQ[.C
} {O)YwT$`
]}kI)34/
R'SBd}1
public String getSFileName() ,eDD:#)$}
{ R:"+ #Sq
return sFileName; Z!=L
} {LP b))
EZ<80G
eJ)1K
public void setSFileName(String value) RU0i#suiz
{ id^|\hDR
sFileName = value; :r&iMb:Ra
} pTWg m\h
,9mgYp2
e8,{|a
public int getNSplitter() h3kaD
{ abBO93f^
return nSplitter; 'WQdr(
} 1 tPVP
87i"
9JPEj-3`g
public void setNSplitter(int nCount) n#BvW,6J
{ IU|kNBo
nSplitter = nCount; y;nvR6)
} r| f-_D
} H?tUCbw
`?|Rc
l-}KmZ]
/* +Q)ULnie e
**Utility.java O|I+],
*/ $Jp~\_X
package NetFox; "(,2L,Zh
mG2VZ>
N5?IpE
public class Utility { ?`"n3!>bS
H<`\bej,
&vkjmiAS
public Utility() p&^J=_O
{ i@5)`<?
^gOww6$<
Z~p!C/B
} zBY~lNB
t<638`{kk
//线程睡眠 YLOwQj'
public static void sleep(int nSecond) nIn2 *r
{ 4(=kE>n}
try{ oQT2S>cm^
Thread.sleep(nSecond); E1 |<Pt
} XWUP=D~
catch(Exception e) X*F_<0RC1
{ 19Ww3PvQ;
e.printStackTrace (); S`m,S4-eD
} j13DJ.xu
} R>2IRvY(
9 |.Ao
//日志 6Ps.E
public static void log(String sMsg) ?59'dGnz_
{ Zw{MgoJ0Z
System.err.println(sMsg); "uKFOV?j&
} B+] D5K
E!J=8C.:
8#X_#
public static void log(int sMsg) >2b`\Q*<
{ rp's
System.err.println(sMsg); '\"G{jU@
} O9s?h3
} icgJ;Q 5
A]o4Mf0>I
Bz /@c)
/* 1%~[rnQ
**TestMethod.java j6S"UwJjp
*/ q.Jsf+
package NetFox; ])w[
|=6_ xRyr
9b"MQ[B4#a
public class TestMethod { UDEj[12S
tfYB_N
_=EKXE)&}
public TestMethod() C ^w)|2o}
{ ///xx/weblogic60b2_win.exe 5o)Y$>T0
try{ 8Pmdk1 ~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0;<)\Wt=i9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3qaMO#{M
SiteFileFetch fileFetch = new SiteFileFetch(bean); .Z\Q4x#!Z
fileFetch.start(); YoKs:e2/:
} $q_R?Eay
catch(Exception e){e.printStackTrace ();} %m&@o~+
&~~wX,6+
8wK ~ i
} }%TPYc
Lrd[Ov
/<Ld'J
public static void main(String[] args) DM{ 4@*]
{ ,"\@fwy{
new TestMethod(); lv%9MW0 z
} -!e7L>w
} s?rBE.g@}
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