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)); c27Zh=;Tj
} ' L-h2
for(int i=0;i<nEndPos.length-1;i++) @o6!
{ ]Na;b
nEndPos = nStartPos[i+1]; Ch)E:Dvq6
} : cPV08i
nEndPos[nEndPos.length-1] = nFileLength; W/.n R[!
} I2gSgv%
} ma6Wr !J
]l}bk]
EX@Cf!GjN
//启动子线程 qOAhBZ~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #V.u[:mO
for(int i=0;i<nStartPos.length;i++) ,U~in)\ U
{ %edTW[C`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .Ms$)1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Rl'xEtaN
nStartPos,nEndPos,i); xLP8*lvy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b_)SMAsO7
fileSplitterFetch.start(); #n+sbx5~7
} ]/|DCxQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b?/Su<q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \[ W`hhJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s >k4G
nEndPos = " + nFileLength); %reW/;)l{
// fileSplitterFetch[nPos.length-1].start(); PHMp,z8
| Pqs)Mb]
ypNeTR$4
//等待子线程结束 Li+|%a
//int count = 0; On}b|ev
//是否结束while循环 93/`e}P"o
boolean breakWhile = false; @h\i<sh!^
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while(!bStop) ]d*O>Pm
{ E O"
write_nPos(); GL^ j |1
Utility.sleep(500); Mo]iVj8~
breakWhile = true; _MTvNs
q)PSHr=Z
2<*Yq8
for(int i=0;i<nStartPos.length;i++) N6v*X+4JH
{ y2PxC. -
if(!fileSplitterFetch.bDownOver) m/WDJ$d
{ z=4E#y`?U
breakWhile = false; \}Kad\)
break; {JM3drnw
} !q8A!P4|'
} 0Qg%48u
if(breakWhile) dBHki*.u
break; mo]>Um'F
bBQHxH}vi
fN 1:'d
//count++; PAiVUGp5[
//if(count>4) NJKk\RM@7
// siteStop(); akQb%Wq
} eTt{wn;6
1(kd3qX
?[ D6|gp
System.err.println("文件下载结束！"); {XW>3 "
} P.~sNd oJ
catch(Exception e){e.printStackTrace ();} {h;i x
} &A^2hPe}
V{{UsEVO
WX+@<y}%
//获得文件长度 0qBXL;sE
public long getFileSize() x!onan
{ M<@9di7c
int nFileLength = -1; r?x~`C
try{ ?hW(5]p|
URL url = new URL(siteInfoBean.getSSiteURL()); lb]k"L%KU7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eh*F/Gu
httpConnection.setRequestProperty("User-Agent","NetFox"); d%Ku'Jy
:$QwOz^N*
U27ja|W^
int responseCode=httpConnection.getResponseCode(); wDs#1`uTq
if(responseCode>=400) ~'):1}KN]
{ QYWl`Yqf
processErrorCode(responseCode); $'lJ_jL
return -2; //-2 represent access is error K$M,d- `b
} l`];CALA4
!p)cP"fa
[ HjGdC
String sHeader; /PkOF((
lqKwjJtX
C,u;l~zz
for(int i=1;;i++) #elaz8 5
{ \)PS&Y8n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EKT"pL-EY
//Utility.log(in.readLine()); Q1 vse
sHeader=httpConnection.getHeaderFieldKey(i); 6:\z8fYD
if(sHeader!=null) s_,&"->
{ C%'eF`
if(sHeader.equals("Content-Length")) b$FXRR\G
{ F,XJGD*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -ANq!$E
break; /h@rLJ)o>
} @HXXhYH
} %;G!gJeE
else 2K'}Vm+
break; ^[zF IO
} l1RFn,Tzr
} OZh+x`' #
catch(IOException e){e.printStackTrace ();} ,@2d4eg4
catch(Exception e){e.printStackTrace ();} < YuI}d~'
\y/+H
W/;qMP1"-
Utility.log(nFileLength); +z\O"zlj
.]Z,O>N
{c$%3iQq
return nFileLength; fGLOXbsA
} .{]=v
R7By=Y!t
0M>%1*
//保存下载信息（文件指针位置） lc0ZfC
private void write_nPos() o6;VrpaNi
{ >l5JwwG
try{ ^F1zkIE
output = new DataOutputStream(new FileOutputStream(tmpFile)); mH3{<^Z6
output.writeInt(nStartPos.length); fKT(.VNq5
for(int i=0;i<nStartPos.length;i++) Va'K~$d_
{ iAWoKW
// output.writeLong(nPos); %K]nX#.B&
output.writeLong(fileSplitterFetch.nStartPos); 0b}lwo,|\
output.writeLong(fileSplitterFetch.nEndPos); ~ .Eln+N
} |m7`:~ow
output.close(); v6?<)M%
} ,K[B/tD{j
catch(IOException e){e.printStackTrace ();} w@2LFDp
catch(Exception e){e.printStackTrace ();} QfM*K.7Sl
} %x7l`.)N
x]U (EX`t$
kLqFh<
//读取保存的下载信息（文件指针位置） H\!u5o&}`
private void read_nPos() cjO,#W0&f
{ `P4qEsZE>`
try{ k .l,>s`!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @.iOFY
int nCount = input.readInt(); >heih%Ar0J
nStartPos = new long[nCount]; rQ$A|GJL
nEndPos = new long[nCount]; JGD{cr[S
for(int i=0;i<nStartPos.length;i++) f1>^kl3@P
{ XsHl%o8,z
nStartPos = input.readLong(); HIeMV,.QN
nEndPos = input.readLong(); (;h]'I@
} +=@Z5eu
input.close(); `ionMTZY
} P-`^I`r
catch(IOException e){e.printStackTrace ();} 4/U]7Y
catch(Exception e){e.printStackTrace ();} _.06^5o
} 49Ue2=PP#
M+^K,
#(*WxVE
private void processErrorCode(int nErrorCode) /ADxHw`k
{ IJXH_H_%*
System.err.println("Error Code : " + nErrorCode); h?YjG^'9
} TJ5{Ee GV
emS+%6U
y$V{yh[:
//停止文件下载 NI s4v(!
public void siteStop() e@,,;YO#4
{ cmN0ya
bStop = true; L{fP_DIa
for(int i=0;i<nStartPos.length;i++) y!!+IeReS
fileSplitterFetch.splitterStop(); PvT8XSlTx!
D&9j$#9Rh
Ef`LBAfOO
} $'FPst8Q<
} ;+b}@e
//负责部分文件的抓取 v|,Hd
**FileSplitterFetch.java v V^GIWK
*/ q%:Jmi>
package NetFox; pmW=l/6+V3
j*:pW;)^
n"K7@[d
import java.io.*; Z ''P5B;
import java.net.*; JN KZ'9
.DvAX(2v
LMG\jc?,
public class FileSplitterFetch extends Thread { x(7K3(#|
H@j^,
b);}x1L.T
String sURL; //File URL o"1us75P
long nStartPos; //File Snippet Start Position j'J*QK&Q
long nEndPos; //File Snippet End Position \+AH>I;vO
int nThreadID; //Thread's ID VYAe!{[
boolean bDownOver = false; //Downing is over Xp?Z;$r$
boolean bStop = false; //Stop identical a@jP^VVk
FileAccessI fileAccessI = null; //File Access interface VD3[ko
T&23Pf1
$^0YK|F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =W|Q0|U
{ Y) t}%62
this.sURL = sURL; .CpF0
this.nStartPos = nStart; YYvs~?bAy
this.nEndPos = nEnd; 99:L#0!.W
nThreadID = id; }b^lg&$(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )eV40l$ M
} #129 i2
#dfW1@m
y14@9<~9
public void run() X0$_KPn
{ Go67VqJr
while(nStartPos < nEndPos && !bStop) T+ t-0k
{ tQ}gBE63
z*[Z:
?3Fo:Z`@F
try{ NR[mzJv
URL url = new URL(sURL); n|*V 8VaL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E37@BfpO3
httpConnection.setRequestProperty("User-Agent","NetFox"); &L?Dogo
String sProperty = "bytes="+nStartPos+"-"; 7f$Lb,\y
httpConnection.setRequestProperty("RANGE",sProperty); =% JDo
Utility.log(sProperty); sq^"bLw
M#>GU<4"
-/qrEKQ0U?
InputStream input = httpConnection.getInputStream(); FTenXJ/c
//logResponseHead(httpConnection); o<'gM]$
]/']{*T1
%%>?<4t
byte[] b = new byte[1024]; Mvh_>-i
int nRead; #"M Pe4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (~GFd7
{ -ur]k]R
nStartPos += fileAccessI.write(b,0,nRead); [Bh]\I'
//if(nThreadID == 1) Ja&%J:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )AoFd>
} j&pgq2Kl
eBV{B70k
ybG)=0
Utility.log("Thread " + nThreadID + " is over!"); i=a LC*@
bDownOver = true; @6!JW(,]\
//nPos = fileAccessI.write (b,0,nRead); `+o.w#cl
} RVsNr rZ
catch(Exception e){e.printStackTrace ();} M Sj0D2H
} _YS+{0 Vq%
} N [u Xo
*^uj(8U
&F}+U#H
//打印回应的头信息 Chup %F
public void logResponseHead(HttpURLConnection con) &B4U)
{ w3Ohm7N[
for(int i=1;;i++) ]>L]?Rm
{ +*DX(v"BH
String header=con.getHeaderFieldKey(i); >cNXB7]E>
if(header!=null) rh&onp O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hrD6r=JT<~
Utility.log(header+" : "+con.getHeaderField(header)); q':wSu u
else <.B s`P
break; dL` +^E>
} ,f+5x]F?m
} 1#<E]<='t
}(K6 YL
bZXNo
public void splitterStop() /<$"c"UQ
{ n:D*r$ C|p
bStop = true; ,Tl5@RN
} kU/=Du
3>" h*U#
4g9b[y~U
} \ c&)8.r
&^_(xgJL
(O2HB-<rY
/* MGzF+ln^U
**FileAccess.java !y`e,(E
*//文件访问(定位，写) C#&6p0U
package NetFox; u&xK>7
import java.io.*; ;NeP&)Td
,<^HB+{Wo
{ NJ>[mKg
public class FileAccessI implements Serializable{ 9VE;I:NO3
8!GLw-kb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H|U/tU-
RandomAccessFile oSavedFile; Ekme62Q>u
long nPos; k#JG
K, 5ax@
/AW>5r]
public FileAccessI() throws IOException `Qf :PX3
{ \cP'#jZz
this("",0); R TUNha^<T
} \q|PHl
3{:<z4>{
rcmAVl:$>
public FileAccessI(String sName,long nPos) throws IOException ; ,<J:%s
{ }>~>5jc/Pg
oSavedFile = new RandomAccessFile(sName,"rw"); ^u!Tyb8Dk
this.nPos = nPos; O)uM&B=
oSavedFile.seek(nPos); AsLjU#jn
} M%s$F@
pHB35=p28
y9li<u<PF
public synchronized int write(byte[] b,int nStart,int nLen) d$rUxqB.
{ o}+Uy
int n = -1; 78CJ
try{ sC_UalOC_
oSavedFile.write(b,nStart,nLen); /2Lo{v=0[
n = nLen; V55J[s*6!
} =awO63j>
catch(IOException e) q)ql]iH
{ ~hslLUE
e.printStackTrace (); 9[{>JRm.
} m2CWQ[u
chmJ|
j& iL5J;
return n; i:M*L< +
} .00=U;H%`
Jav2A6a
]}7rWs[|1
} (TNY2Ke2 8
7b,,%rUd
J%:/<uCmZ
/* 4)+IO;
**SiteInfoBean.java %Rep6=K*$
*/ a@y5JxFAy
package NetFox; +c8AbEewg
Y\e]2
,/`E|eG1G
public class SiteInfoBean { K6{bYho
Va Yu%
&^n>ZY,
private String sSiteURL; //Site's URL >2CusT2
private String sFilePath; //Saved File's Path b]<HhU
private String sFileName; //Saved File's Name VNrO(j DUv
private int nSplitter; //Count of Splited Downloading File MJKl]&
cYM~IA
U+PCvl=x
public SiteInfoBean() #C1A5JE&
{//nSplitter的缺省值为5 ,r 2VP\hLh
//default value of nSplitter is 5 k5t^s
this("","","",5); )s<WG}
} Yuo1'gE+
).}k6v[4)
BU:Ecchbr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [AX"ne#M*
{ [TK? P0
sSiteURL= sURL; +'['HQ)
sFilePath = sPath; |@ZqwC=
sFileName = sName; (#B^Hyz!
this.nSplitter = nSpiltter; 6{+_T
P%+or*
Wda\a.bXT
} P"9@8aLB
0L0Jc,(F+
3Wb2p'V7$?
public String getSSiteURL() @?3vRs}h
{ 1Y"35)CR)
return sSiteURL; =Esbeb7P
} nl'J.dJe
z/0yO@_D/q
}WO9!E(
public void setSSiteURL(String value) WiNr866nB
{ J[!x%8m
sSiteURL = value; K)Zkj"y
} Z?(4%U5z
6I&j cHH
aXIB) $1
public String getSFilePath() UOu6LD/|h
{ 6c2ThtL
return sFilePath; R] Disljq
} "VDk1YX_&l
nEd M_JPv
u*26>.
public void setSFilePath(String value) *"ykTqa
{ L8:]`MQ0
sFilePath = value; chO'Q+pw
} y)p$_.YFF
EItxRHV5
2~M;L&9-
public String getSFileName() eA1k)gjE
{ 8K.s@<
return sFileName; oE!hF}O
} i'!jx.
cBab2/
8lOZIbwS
public void setSFileName(String value) BZJKiiD
{ C!7U<rI
sFileName = value; @1<omsl
} Ehb?CnV#J
T/wM(pr'
TwM1M["3
public int getNSplitter() ,b6kTQq
{ nY{i>Y
return nSplitter; NokXE
} U~{Sa+
'f-
HZDk <aU/!
public void setNSplitter(int nCount) { r6]MS#l1
{ MUbhEau?
nSplitter = nCount; 5;FP.{+
} V<i<0E
} pxw{
\;-=ODC
J4gI=@e
/* d&aBs++T
**Utility.java #D`S
*/ *CeQY M
package NetFox; ;Ze"<U
5jn$7iE`
?CH?kP
public class Utility { j`2B}@2
MV0<^/p|
4ef*9|^x#
public Utility() _YH<YOrMh
{ #0P!xZ'|{
2f3=?YqD
v78&[
} W[R]^2QAG
$zC6(C(l
//线程睡眠 csK>iN
public static void sleep(int nSecond) UvPp~N7,
{ M MAAHo
try{ ?_VRfeztw
Thread.sleep(nSecond); *he7BUO
} e> ar
catch(Exception e) h`?y2?O
{ Hs[}l_gYn
e.printStackTrace (); o-SRSu
} C!!mOAhJ
} H9%l?r5
[urH a
//日志 )UR1E?'
public static void log(String sMsg) #mgA/q?A
{ [zY!'cz?
System.err.println(sMsg); QjQ4Z'.r>
} YO)')&
LIr(mB"Y0
%S{o5txo
public static void log(int sMsg) nHSTeFI?
{ qPsyqn?Y|
System.err.println(sMsg); d4d\0[
} &bB6}H(
} oz%h)#;
/"(b.&
wX-RQ[2X
/* {V[Ha~b%*
**TestMethod.java ;US83%*
*/ dKU5;
package NetFox; %z1{Kus
65lOX$*{-
pz$_W
public class TestMethod { c`-YIz)W
pAENXC\,
(tJ91SBl
public TestMethod() Qn*6D
{ ///xx/weblogic60b2_win.exe [/?c@N,
try{ v-ThdE$G#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^[en3aQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6/|U
SiteFileFetch fileFetch = new SiteFileFetch(bean); c2/FHI0J;
fileFetch.start(); rW[SU:
} DWuRJ
catch(Exception e){e.printStackTrace ();} mDZ=Due1
(Ar?QwP9>
~Y% : 3
} .SG0}8gW
#xlZU
y0;,dv]
public static void main(String[] args) 8,=G1c
{ 9QX4R<"wUg
new TestMethod(); l#Yx TY
} 7k>zuzRyF
} Fl<(m
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