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)); <v ub Q4
} Cq@7oi]W0
for(int i=0;i<nEndPos.length-1;i++) %>&~?zrq
{ a,rXG
nEndPos = nStartPos[i+1]; _9oKW;7f7
} (R=ZI
nEndPos[nEndPos.length-1] = nFileLength; #h ud_
} `&I6=,YLp
} ~ESw* 6s9
j1Ys8k%$l
{9J|\Zz3
//启动子线程 W3l[a^1d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d{TcjZ
for(int i=0;i<nStartPos.length;i++) +@$VJM%^7b
{ hl[<o<`Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yXkQ ,y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /{({f?k<\/
nStartPos,nEndPos,i); C,;?`3bH@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !,-'wT<v
fileSplitterFetch.start(); zGe =l;
} fq1w <e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6l|L/Z_6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :qS~"@?<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Qc33CA
nEndPos = " + nFileLength); r E1ouz!D
// fileSplitterFetch[nPos.length-1].start(); H#F"n"~$
W}F~vx.
f$</BND
//等待子线程结束 t<`wK8)
//int count = 0; s"7FmJ\7rw
//是否结束while循环 *K>2B99TXu
boolean breakWhile = false; 2U%t
!:d\A
#WA7}tHb
while(!bStop) W)`>'X`
{ EQnU:a
write_nPos(); C&F% j.<
Utility.sleep(500); [YQtX_;w
breakWhile = true; oCwep^P(v
bO6z;D#
"-fyX!
for(int i=0;i<nStartPos.length;i++) ~#EXb?#uS
{ gISA13
if(!fileSplitterFetch.bDownOver) Pf8_6z_
{ [:,|g;=Y}
breakWhile = false; ~+6#4<M.~
break; C&q}&=3r
} Uq=Rz8hLM
} &WCVdZK:
if(breakWhile) XffHF^l9F
break; ;[zZI~wh
`zs@W
_2k<MiqCD[
//count++; GDj_+G;tO\
//if(count>4) ?,v@H$)3_
// siteStop(); wPyc?:|KD?
} ;J?fK69%
^=I[uX-3ue
sS)tSt{C
System.err.println("文件下载结束！"); zv1,DnkqF
} kPEU}Kv
catch(Exception e){e.printStackTrace ();} 823y;
} YC{7;=Pf
Vg(p_k45`
uPFbKSJj
//获得文件长度 9<Zm}PE32
public long getFileSize() VQ~eg wJL
{ 84(jg P
int nFileLength = -1; 1_~'?'&^
try{ PC=s:`Y}R
URL url = new URL(siteInfoBean.getSSiteURL()); PVKq&Q?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N}|1oQkjf
httpConnection.setRequestProperty("User-Agent","NetFox"); PHsM)V+
NFU=PS$
4yu=e;C wy
int responseCode=httpConnection.getResponseCode(); D-e^b'l
if(responseCode>=400) kSJ:4!lFU
{ k \t6b1.M
processErrorCode(responseCode); d76C]R5L
return -2; //-2 represent access is error Y5>'(A>
} LQ$dT#z2A
Xp^>SSt:4
B]D51R\}VE
String sHeader; X bV?=
-r_Pp}s
XF4NRs
for(int i=1;;i++) RvW>kATb_F
{ m[5ed1+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lKirc2
//Utility.log(in.readLine()); Qe<c@i"
sHeader=httpConnection.getHeaderFieldKey(i); Tq6@ 1j6p
if(sHeader!=null) QD[l 6
{ IetV]Ff6
if(sHeader.equals("Content-Length")) P.|g4EdND
{ ~fA H6FdZ\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,g)9ZP.F
break; w68VOymD/
} I>3G"[t
} RML'C:1
else Zfr?(y+3
break; * 8D(Lp1
} el0W0T
} TwE&5F*
catch(IOException e){e.printStackTrace ();} Lj3q?>D*^6
catch(Exception e){e.printStackTrace ();} [h :FJ
I'cM\^/h
,wra f#UdP
Utility.log(nFileLength); HQ|{!P\/?U
LZ9IE>sj
6~+?DIc
return nFileLength; *Oe;JqQkK
} 7w"YCRKh
s&OwVQ<M
rNHV
//保存下载信息（文件指针位置） |z%*}DPrpa
private void write_nPos() CV,[x[L#{
{ qoD M!~
try{ j[1^#kE
output = new DataOutputStream(new FileOutputStream(tmpFile)); u`X}AKC
output.writeInt(nStartPos.length); U#_rcu
for(int i=0;i<nStartPos.length;i++) -Kf'02
{ +%RXV~
// output.writeLong(nPos); `!T6#6h
output.writeLong(fileSplitterFetch.nStartPos); 785Y*.p
output.writeLong(fileSplitterFetch.nEndPos); 2|^bDg;W+u
} ].w$b)G
output.close(); 65A>p:OO
} e.g$|C^$m
catch(IOException e){e.printStackTrace ();} (3G]-
catch(Exception e){e.printStackTrace ();} k@R)_,2HH
} D#9W [6
KK*"s^L
w4+bzdZ
//读取保存的下载信息（文件指针位置） kjW`k?'s
private void read_nPos() IF*kLl?
{ {GH 0 J"
try{ 1z(y>`ZBq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >&9Iy"
int nCount = input.readInt(); C>7k|;BvF
nStartPos = new long[nCount]; `qsn;
nEndPos = new long[nCount]; eVWnD,'
for(int i=0;i<nStartPos.length;i++) ]HP
{ e{9(9qE"
nStartPos = input.readLong(); Ad7=JzV
nEndPos = input.readLong(); [!:.9
} Hv>Hz*s_I
input.close(); BO ^T :
} =l3*{ ?G
catch(IOException e){e.printStackTrace ();} 3'6>zp
catch(Exception e){e.printStackTrace ();} Z-j%``I?h
} pr-!otz
|5,q54d(K
,G,T&W
private void processErrorCode(int nErrorCode) e~weYGK
{ {/ _.]Vh
System.err.println("Error Code : " + nErrorCode); $NWI_F4
} r).S/
Fx0<!_tY-
[OsW
//停止文件下载 C`x>)wm:
public void siteStop() 7b T5-=.
{ m5LP~Gb
bStop = true; DI!l.w5P_
for(int i=0;i<nStartPos.length;i++) Wcn^IQ
fileSplitterFetch.splitterStop(); D058=}^HE
B: uW(E
'gE_xn7j
} aARm nV
} EY!aiH6P
//负责部分文件的抓取 8DLMxG
**FileSplitterFetch.java @,sg^KB
*/ ? B^*YCo7(
package NetFox; 4 ITSDx
15gI-Qb
Wm.SLr,o0
import java.io.*; rq6(^I
import java.net.*; p2y h
I)O-i_}L&K
cEw/F0
public class FileSplitterFetch extends Thread { {N;XjV1x
5kJ>pb$/
`h Y:F(
String sURL; //File URL U]ouBG8/
long nStartPos; //File Snippet Start Position +Mv0X%(N
long nEndPos; //File Snippet End Position `^afbW
int nThreadID; //Thread's ID J2H8r 'T
boolean bDownOver = false; //Downing is over J(-#(kMyf
boolean bStop = false; //Stop identical $X-,6*
FileAccessI fileAccessI = null; //File Access interface Fu m1w
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f=J#mmHw$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c:~o e
{ Z!|nc.
this.sURL = sURL; /)y~%0
this.nStartPos = nStart; /{1xpR
this.nEndPos = nEnd; mrd(\&EhA
nThreadID = id; lTdYPqMi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r"rID RQ"
} Mp$ uEi
hgKs[ySo,3
"mT~_BsD
public void run() bU:"dqRm<
{ ^#%$?w>wI
while(nStartPos < nEndPos && !bStop) sbNCviKP
{ k2*^W&Z
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WE`Y!
try{ |vWx[=`o
URL url = new URL(sURL); *+qXXCA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jp5~iC2d
httpConnection.setRequestProperty("User-Agent","NetFox"); S`X;2\:
String sProperty = "bytes="+nStartPos+"-"; X'[SCs
httpConnection.setRequestProperty("RANGE",sProperty); T?7ZF+yo6
Utility.log(sProperty); OjeM#s#N!
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j|HOry1E&
InputStream input = httpConnection.getInputStream(); 6z=:x+m
//logResponseHead(httpConnection); =UNzjmP503
wTIOCj
/2?GRwU~P
byte[] b = new byte[1024]; Fz)z&WT
int nRead; t_@%4Wn!1L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {v]A`u)
{ c+|,2e 0T
nStartPos += fileAccessI.write(b,0,nRead); a50{gb#
//if(nThreadID == 1) zc,fJM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &sWqSS
} U#,2et6
XF{}St~(
31YzTbl[H
Utility.log("Thread " + nThreadID + " is over!"); le|e 4f*+
bDownOver = true; d%4!d_I<
//nPos = fileAccessI.write (b,0,nRead); 6]Ppa ~Xwq
} tq>QZEg
catch(Exception e){e.printStackTrace ();} eyl+D sK
} ga~rllm;i
} Sjj&n S
qz(0iZ]Y
Ge[N5N>
//打印回应的头信息 S4`uNB#Ht
public void logResponseHead(HttpURLConnection con) |{Z?a^-NJ
{ PGu6hV{
for(int i=1;;i++) =}U`q3k
{ Alp9] 0(
String header=con.getHeaderFieldKey(i); K}! VY`
if(header!=null) ep,kImT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OYNs1yB
Utility.log(header+" : "+con.getHeaderField(header)); ~XQN4Tv-
else a{69JY5
break; (?YTQ8QR
} +&-/$\"
} nvsuF)%9hZ
Kv!CL9^LX7
nY}Ep\g
public void splitterStop() i v&:X3iB
{ Gv6EJV1i
bStop = true; ],&WA?>G
} >,A:zbs&
vQ26U(7\>
qeSxE`E"
} I`E9]b(w
>K;p+( <6
8KT|ixs
/* m[Px|A5{
**FileAccess.java m_Z%[@L
*//文件访问(定位，写) XrtB&h|C
package NetFox; }N*6xr*X+
import java.io.*; i@Q)`>4
4wMKl6mL
LYkW2h`JQ
public class FileAccessI implements Serializable{ *w59BO&M4
0b~5i-zM/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y*B}^!k6
RandomAccessFile oSavedFile; {Qg"1+hhM
long nPos; E,u@,= j
L5of(gQ5]
\BbemCPAm
public FileAccessI() throws IOException "f(iQI
{ z';p275
this("",0); r^VH [c@c
} !ZD[ $lt+
n4qj"xQ
.& B_\*
public FileAccessI(String sName,long nPos) throws IOException %{5mkO&,2
{ FSIV\ u
oSavedFile = new RandomAccessFile(sName,"rw"); d1D{wZ3g
this.nPos = nPos; RAR"9 N .
oSavedFile.seek(nPos); $2 ~RZpS
} `8KWZi4 ]
2zh?]if
b,$H!V*
public synchronized int write(byte[] b,int nStart,int nLen) #ZRQVC;b;
{ QOcB ]G
int n = -1; G?8LYg!-
try{ ePa1 @dI
oSavedFile.write(b,nStart,nLen); \ :1MM
n = nLen; $F`jM/B6
} 8 POrD8B
catch(IOException e) J,_I$* _0
{ k6QQoLb$V
e.printStackTrace (); T`Sp!
} BPIp3i
smF#'"{
8AOJ'~$
return n; 8sx\b
} P'KaWu9z
(SfP3
12~zS
} wtndXhVC4>
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[58xT>5`m
/* 5<<e_n.2q
**SiteInfoBean.java <}pqj3
*/ a9(1 6k
package NetFox; Aj*0nV9_
]tanvJG}'
>w9fFm!Q
public class SiteInfoBean { ~2beVQ(U
UsNr$MO {
d>M&jSCL
private String sSiteURL; //Site's URL ;m,lS_[c
private String sFilePath; //Saved File's Path MP-A^QT
private String sFileName; //Saved File's Name J@=1zL
private int nSplitter; //Count of Splited Downloading File KCGs*kp>
/iQ}DbtRb
&G@(f=
public SiteInfoBean() Y [0S
{//nSplitter的缺省值为5 BBm.;=8@ ^
//default value of nSplitter is 5 <fCgU&
this("","","",5); t7H2z}06=h
} Yc3r3Jy
{l-,Jbfi`
KN'l/9.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Vrf2%$g
{ |qE"60&"}
sSiteURL= sURL; 1c(1YGuH
sFilePath = sPath; MGCwT@P
sFileName = sName; ^VR1whCrx
this.nSplitter = nSpiltter; 8*;G\$+
Z=_p
wciYv,
} U59uP 7n
.taJCE
#r `hK)
public String getSSiteURL() R4"["T+L`
{ LS{g=3P0
return sSiteURL; zU:zzT}|TZ
} v(3nBZHv_!
a.v$+}+.[,
GrGgR7eC#P
public void setSSiteURL(String value) X4>c(1e
{ h `d(?1
sSiteURL = value; su<_?'uH
} VZ&>zF
LDN'o1$qo
sZ{Kl\1@
public String getSFilePath() =iC5um:
{ [R)?93
return sFilePath; Q*+@"tk<
} E j@M\
)#l &F$
hun LV8z
public void setSFilePath(String value) a5{CkM&,(
{ yb1A(~
sFilePath = value; .^N+'g
} *,-)4)7d
-@b&qi7&S
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public String getSFileName() m=k(6
{ !s/ij'T
return sFileName; %@'9<i8o
} +V4BJ/H
o^wj_#ai$
WZ&/l 65J
public void setSFileName(String value) - o$S=
{ 6cp x1y]~6
sFileName = value; +j_Vs+0
} XL_X0(AKf
"5BgajrB
eC%.xu^
public int getNSplitter() Zk$AAjC&
{ ZalG/PFy
return nSplitter; KS}Ci-
} .Ej `!
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fw ._
public void setNSplitter(int nCount) W%hdS<b
{ J)Dw`=O0n
nSplitter = nCount; }UMg ph:2:
} 4NUCLr7Y
} e2*0NT^R
9-eYCg7C|
1 h|cr_
/* E)o/C(g
**Utility.java HuBG?4Qd
*/ &NZN_%
package NetFox; r+3V+:f
FjRJSMwO,
*Af]?-|^{#
public class Utility { :T"!6;
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Wznz
public Utility() )TJz'J\*
{ 9Gfm?.O5
s@OCj0'l
X ~%I(?OX
} @y[Zr6\z
L^yQb4$&M
//线程睡眠 E D*=8s2
public static void sleep(int nSecond) Ij(S"P@
{ YN_#x
try{ RQWVjF#
Thread.sleep(nSecond); t }7hD
} PwQW5,,h0
catch(Exception e) ,w,>pO'[
{ #R4Mv(BG
e.printStackTrace (); I:U/%cr,
} 7f8%WD)
} H[@uE*W
TyD*m$`y
//日志 \)eHf 7H
public static void log(String sMsg) ~0w7E0DE[
{ J5)e 7
System.err.println(sMsg); ,w; ~R4x
} VQU[5C
C6,GgDH`
LO[1xE9
public static void log(int sMsg) eW"i'\`0
{ {/uBZ(
System.err.println(sMsg); W:O<9ZbQ_
} ~:b bV6YO
} F7^8Ej9*a
e &^BPzg
t1b$,jHmKl
/* YN?@ S
**TestMethod.java L!V`Sb
*/ 3H%R`ha
package NetFox; jWLZ!a3+
.{`+bT^b<2
qGuz`&i
public class TestMethod { jFM8dl n
0*L|rJf
`!S5FE"-
public TestMethod() wYSvI
{ ///xx/weblogic60b2_win.exe 4q/E7n
try{ Fkuq'C<|Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D;Fvd:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >9a%"<(2#
SiteFileFetch fileFetch = new SiteFileFetch(bean); V"%2Tz
fileFetch.start(); -}%'I]R=
} R"6Gm67t
catch(Exception e){e.printStackTrace ();} Kv:UQdnU[
>s1FTB-$W
&JAQ:([:
} J_}&Btb)e
6#T?g7\pyR
|w- tkkS
public static void main(String[] args) [6V'UI6
{ ><"5 VwR
new TestMethod(); K~<pD:s
} $Rv}L'L
} ?Pw#!t
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