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)); 5RSP.Vyx{
} `;Fs
for(int i=0;i<nEndPos.length-1;i++) sY}0PB
{ 4]cr1K ^
nEndPos = nStartPos[i+1]; D_w<igu!3
} `V[ hE r|
nEndPos[nEndPos.length-1] = nFileLength; q^[SN
} 0|rdI,z
} PXDJ[Oj7(0
,;=is.h9
<z wI@i
//启动子线程 <j_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gX5.u9%C\
for(int i=0;i<nStartPos.length;i++) # o\&G@e}
{ bU4\Yu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1eS@ihkP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fAT M?
nStartPos,nEndPos,i); DK%@[D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w*4sT+ P
fileSplitterFetch.start(); sR$/z9w
} aU] nh. a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c 8|&Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0gKSjTqo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~Z97L
nEndPos = " + nFileLength); 4Rl~7|
// fileSplitterFetch[nPos.length-1].start(); Op iVQr:
lYrW"(2
<+`}: A
//等待子线程结束 |e&hm ~R1
//int count = 0; Hn?v/3
//是否结束while循环 xl@
boolean breakWhile = false; &!8u4*K5j
?)/H8n
+|O&k
while(!bStop) ?,!C0ts
{ _^w^tfH]
write_nPos(); tlmfDQD
Utility.sleep(500); 4?7OP t6
breakWhile = true; O~F8lQ
%e=UYBj"
l]P3oB}Yo
for(int i=0;i<nStartPos.length;i++) *3y:Wv T>
{ 1ZfhDtK(
if(!fileSplitterFetch.bDownOver) -s6;IoG/
{ Snas:#B!
breakWhile = false; g6q67m<h
break; ] 2lhJ
} @p7*JLO
} F[oTc^dr
if(breakWhile) F:2V;
break; </h}2x
|H-zm&h>'
t=r*/DxX=
//count++; h4? 'd+K
//if(count>4) 6\/(TW&
// siteStop(); &28%~&L
} 2-u9%
f(*^zga,
)}R w@70L-
System.err.println("文件下载结束！"); Q-f?7*>
} Gn?<~8a
catch(Exception e){e.printStackTrace ();} z_ia3k<
} >z69r0)>
cpBTi
5!d'RBO
//获得文件长度 oOy_2fwZPp
public long getFileSize() j}@n`[V1
{ ns !Mqcm
int nFileLength = -1; 4VfZw\^
try{ Q>>II|~;J
URL url = new URL(siteInfoBean.getSSiteURL()); l=t$XWh!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q{oppali
httpConnection.setRequestProperty("User-Agent","NetFox"); \MFjb IL
1mz72K
!5[5l!{x
int responseCode=httpConnection.getResponseCode(); 2z027P-Q
if(responseCode>=400) x]jJ
{ U>kL|X3 V
processErrorCode(responseCode); *`wgqin
return -2; //-2 represent access is error A;C)#Q/
} G8!* &vR/
7 a_99?J
\TXCq@
String sHeader; #R3|nL
$2gZpO|
=LMM]'no,
for(int i=1;;i++) '#@tovr
{ Oi4tG&q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "~/O>.p
//Utility.log(in.readLine()); dgM@|&9*m
sHeader=httpConnection.getHeaderFieldKey(i); ~5b^Gvb?
if(sHeader!=null) q`^T7
{ E >lW'
if(sHeader.equals("Content-Length")) d;O4)8>
{ O;?Nz:/q
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uu+)r
break; *.F4?i2D
} use` y^c
} 'Q F@@48
else #Vi:-zyY
break; Y|96K2BR
} j?y_ H[Z
} rRzc"W}K+
catch(IOException e){e.printStackTrace ();} MF/@Efjn ]
catch(Exception e){e.printStackTrace ();} &i?>mt
zsuXN*
Ub-q0[6
Utility.log(nFileLength); 'PVxc%[
Rk@xv;t;
2VyJ
return nFileLength; vX/("[
} b;%>?U`>p
:927y
&pZncm
//保存下载信息（文件指针位置） tDIQ=
private void write_nPos() d/Y#oVI
{ wmnh7'|0u
try{ MGE8S$Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); QNesiV0MI
output.writeInt(nStartPos.length); wPrqFpf
for(int i=0;i<nStartPos.length;i++) /[RO>Z9
{ #[.aj2
// output.writeLong(nPos); | )M>;q
output.writeLong(fileSplitterFetch.nStartPos); o6T'U#7P
output.writeLong(fileSplitterFetch.nEndPos); C6{\^kG^j2
} 5>u,Qh
output.close(); )7s(]~z
} U/l3C(bc!
catch(IOException e){e.printStackTrace ();} }*9mNE
catch(Exception e){e.printStackTrace ();} \olYv!f
} I$w:qS&:
Iu|4QE
X/' t1
//读取保存的下载信息（文件指针位置） w=feXA3-S
private void read_nPos() /@QPJ~%8Ud
{ @pkQ2OM 2
try{ Usz O--.C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ap|$8G
int nCount = input.readInt(); T_/ n#e
nStartPos = new long[nCount]; 0l+[[ZTV
nEndPos = new long[nCount]; ^^Te
for(int i=0;i<nStartPos.length;i++) @K=C`N_22
{ GZWU=TC2{2
nStartPos = input.readLong(); GW;O35 m
nEndPos = input.readLong(); #4BwYj(Sl
} GLtd6;V
input.close(); SA[wFc
} iw\yVd^]:k
catch(IOException e){e.printStackTrace ();} ^M6R l0
catch(Exception e){e.printStackTrace ();} I)wc&>Lc
} BH\!yxK
_-5|"oJ
]CxDm
private void processErrorCode(int nErrorCode) zSo(+D &[
{ o4F(X0
System.err.println("Error Code : " + nErrorCode); Zb}U 4
} r"xs?P&/$
f6k=ew
S}/5W
//停止文件下载 !M@jW[s
public void siteStop() PB(I3R9
{ $QB/n63
bStop = true; <kOdd)X
for(int i=0;i<nStartPos.length;i++) @ q:S]YB
fileSplitterFetch.splitterStop(); &5d~ODO
;(r,;S_`0
5u=>~yK+
} X([p0W 9V(
} :`>bh
//负责部分文件的抓取 {j[a'Gb
**FileSplitterFetch.java 92XG|CWX
*/ oFL7dL
package NetFox; Gw-y6e'|Y
T7R,6qt
r%\%tz'`j
import java.io.*; %i5tf;x6i
import java.net.*; $q*hE&x Qd
C8t;E`
e82xBLxR%
public class FileSplitterFetch extends Thread { x,M8NTb*
A"i$.dR{
ZgA+$}U)uW
String sURL; //File URL .oH)eD
long nStartPos; //File Snippet Start Position i[/`9 AK
long nEndPos; //File Snippet End Position z07Xj%zX9
int nThreadID; //Thread's ID 2$TwD*[
boolean bDownOver = false; //Downing is over 8h,=yAn5
boolean bStop = false; //Stop identical .s-*aoj
FileAccessI fileAccessI = null; //File Access interface D=@bPB>
7!/!a*zg
e?_uJh"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException = P$Q;d
{ W$xW9u8@+(
this.sURL = sURL; O;+ sAt
this.nStartPos = nStart; &lnM 1W
this.nEndPos = nEnd; Ubm]V{7
nThreadID = id; COA*Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qv6-,6<
} P:%r3F
d.yATP
of8 >xvE|
public void run() ]w_JbFmT
{ QD^q\9U[
while(nStartPos < nEndPos && !bStop) [\-)c[/
{ `*",_RO;
>u+%H vzc
|eI!wgQx
try{ p^k*[3$0
URL url = new URL(sURL); Zu/w[*;M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L$6W,D
httpConnection.setRequestProperty("User-Agent","NetFox"); B$ jX%e{:S
String sProperty = "bytes="+nStartPos+"-"; ^h!}jvqE
httpConnection.setRequestProperty("RANGE",sProperty); 4Z.Dz@.c(
Utility.log(sProperty); mJZB@m u?
-QK-w>
xX.kKEo"d
InputStream input = httpConnection.getInputStream(); '*D>/hn|:]
//logResponseHead(httpConnection); .iYp9?t
W.BX6
<:4b4Nl
byte[] b = new byte[1024]; SZvp%hS0
int nRead; ipyc(u6Z5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L)c]i'WZ
{ a66Ns7Rb
nStartPos += fileAccessI.write(b,0,nRead); _*ar\A`
//if(nThreadID == 1) XhUVDmeUMb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XtqhK"f%
} ,\T7{=ZG\!
q$PO.#
{F;"m&3Lt
Utility.log("Thread " + nThreadID + " is over!"); {r%T_BfY
bDownOver = true; '^`iF,rg
//nPos = fileAccessI.write (b,0,nRead); wZVLpF+7
} XT?wCb41R
catch(Exception e){e.printStackTrace ();} Clb7=@f
} 7(d#zu6n
} *dN_=32u
KM?w{ ~9
-S#jOr
//打印回应的头信息 3_8W5J3I
public void logResponseHead(HttpURLConnection con) Qb|@DMq%
{ .bUj
for(int i=1;;i++) YJ|U|[
{ p8FXlTk
String header=con.getHeaderFieldKey(i); D$+g5u)
if(header!=null) _nM 7SK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hk'R!X
Utility.log(header+" : "+con.getHeaderField(header)); /U})mdFm
else <G'M/IR a
break; md `=2l
} zkquXzlgB
} >qBJK)LHOv
-]t>'Q?
9/_~YY=/h
public void splitterStop() :D4'x{#H
{ ]FgKL0
bStop = true; iBwM]Eyv.
} r uIgoB
Xzl$Qc
Xck`"RU<xA
} =;(L$:l~
~E/=nv$
v#EFklOP
/* [8Fn0A
**FileAccess.java ?aI.Z+#
*//文件访问(定位，写) M:dH>
package NetFox; !f]kTs]j~
import java.io.*; BS ]:w(}[
T;]Ob3(BpW
(\'$$
public class FileAccessI implements Serializable{ f[ KI T
o/ 7[ G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [RY Rt/?Q
RandomAccessFile oSavedFile; J=&}$
long nPos; P| hwLM
*s<cgPKJ@
G1\F7A
public FileAccessI() throws IOException vCXmu_S4^>
{ w ^?#xU1.i
this("",0); 2x<!>B
} Fy0sn|
pXvys]@
T$<yl#FY
public FileAccessI(String sName,long nPos) throws IOException 3.1%L"r[)
{ )7X$um
oSavedFile = new RandomAccessFile(sName,"rw"); RB6Q>3g
this.nPos = nPos; $N Mu
oSavedFile.seek(nPos); F`GXho[
} *tv\5KW G
G4rzx%W?
hiEYIx
public synchronized int write(byte[] b,int nStart,int nLen) mkhWbzD'S
{ _8!x
int n = -1; 0X4)=sJP
try{ -2(?O`tZ
oSavedFile.write(b,nStart,nLen); IMBjI#\
n = nLen; R1/c@HQw?
} =XK}eQ_d
catch(IOException e) |KY-kRN7
{ <LzxnTx=
e.printStackTrace (); V%z?wDC
} ens]?,`0
t\}_WygN
<EQaYZY=
return n; z;y{QO
} s;..a&C'
B"zB=Aw
Xk/iyp/
} xcn~KF8
z>\l%_w
|>[qC O
/* q]?)c
**SiteInfoBean.java lHDZfwJ&C1
*/ G0~Z|P
package NetFox; 8};kNW^2m
KVr9kcs
GzBPI'C
public class SiteInfoBean { ,k=8|=aF
~#i2reG5
/.=aA~|
private String sSiteURL; //Site's URL CBF<53TshR
private String sFilePath; //Saved File's Path lSlZ^.&
private String sFileName; //Saved File's Name QnP?j&
private int nSplitter; //Count of Splited Downloading File G+Bk!o
cTS.yN({G
\#WWJh"W
public SiteInfoBean() jvAjnh#
{//nSplitter的缺省值为5 ;]b4O4C\
//default value of nSplitter is 5 TLp2a<Iy
this("","","",5); a DXaQ
} O!^ >YvOh
KeRC8mYp
xm1'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #"lb9._M
{ /!^,+
sSiteURL= sURL; *^Ges;5$"
sFilePath = sPath; 9bM kP2w>
sFileName = sName; 4c95G^dZ
this.nSplitter = nSpiltter; UCK;?]
0[M2LF!m
|Olz h63k:
} `/'p1?Z"
1G.?Y3DC<
TnKv)%VF
public String getSSiteURL() l qwy5#
{ [z ]P5
return sSiteURL; y.}{KQ"a*
} ,msP(*qoI
1G"ohosmF
*S"RU~1_
public void setSSiteURL(String value) dP(.l}O
{ /d,u"_=l
sSiteURL = value; ~*"ZF-c,
} C:}1r
T/2k2r4PD
]jC{o,?s
public String getSFilePath() h#KSKKNW
{ bmK
return sFilePath; 1#%H!GKvTU
} ot[ZFF\
AIY 1sSK
c*.
public void setSFilePath(String value) LTo5v
{ F8dr-"G
sFilePath = value; 8>W52~^fU
} Du65>O
8h }a:/
*~shvtq
public String getSFileName() U#S-x5Gn
{ 2oV6#!{Z
return sFileName; sve} ent
} D!! B4zt
t!SxJB e
WeaT42*Q{
public void setSFileName(String value) ~3M8"}X;L
{ {6GX ?aw'
sFileName = value; az:}RE3o
} 1 :$#a
)^AZmUYZ
\8!CKnfs
public int getNSplitter() {U$XHG
{ R]e&JoY
return nSplitter; yP"}(!~m
} H"(#Tp ZTE
=}Zl E
sR>>l3H
public void setNSplitter(int nCount) fS/:OnH
{ M>Tg$^lm
nSplitter = nCount; }2LWDQ;po
} %&&)[
} }4!}vkVx
LKp;sV
3<+ZA-2
/* V0Oqq0\
**Utility.java }BU%<5CQ
*/ l0`bseN<
package NetFox; 0m]QQGvJ{
F~fBr
T9&{s-3*
public class Utility { }T(=tfv@
~!~i_L\V
u&uFXOc'
public Utility() &g&,~Y/z;
{ JygJ4RI%j
3^%2,
,7bhUE/VB
} M1Ff ,]w
,cS#
//线程睡眠 &'&)E((
public static void sleep(int nSecond) +DXP&Q
{ fX 1%I
try{ KYw7Jx`l
Thread.sleep(nSecond); iY$iL<
} E56
catch(Exception e) 6'kQ(r>
{ 0$c(<+D
e.printStackTrace (); e ar:`11z
} U)Hc7% e
} X>yDj]*4P
)Jk$j
//日志 "5<!
public static void log(String sMsg) ><D2of|
{ &8l?$7S"_/
System.err.println(sMsg); aReJ@
} 0C%IdV%CU
lSaX!${R'T
XXn3K BIf
public static void log(int sMsg) xtD(tiqh.;
{ T=u"y;&L
System.err.println(sMsg); p*42 @1,
} ,(Zxd4?y
} BXU0f%"8U
`<d.I%}
G^nG^HTo5
/* ^gx~{9`RR
**TestMethod.java xBc|rqge
*/ -O?HfQ
package NetFox; CF','gPnc
BK4S$B
d3q.i5']G
public class TestMethod { Qd YYWD
u28$V]
I50LysM
public TestMethod() A|1xK90^XT
{ ///xx/weblogic60b2_win.exe !9NF@e'&!
try{ BWxJ1ENM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "1^tVw|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Ugc:L<h+
SiteFileFetch fileFetch = new SiteFileFetch(bean); #~/9cVm$
fileFetch.start(); (0Br`%!F
} )#M$ov
catch(Exception e){e.printStackTrace ();} )#i"hnYpQ
Y% \3N
N}%AUm/L
} *j]Bo,AC
7L&,Na
+C7E]0!r
public static void main(String[] args) }JST(d&
{ N atC}k
new TestMethod(); v5\ALWy+p
} GB}\7a
} HAI)+J
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