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)); /~40rXH2C
} +7V=aNRlE
for(int i=0;i<nEndPos.length-1;i++) 8y$5oD6g9
{ OmB TA=E<
nEndPos = nStartPos[i+1]; tY/En-&t
} Hx$.9'Oq\Q
nEndPos[nEndPos.length-1] = nFileLength; sffhPX\I
} jm+ V$YBP
} ?4^};wDb2
{!L=u/qs"
?-e7e%
//启动子线程 ^6Yd}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8tU>DJ}0
for(int i=0;i<nStartPos.length;i++) R7lYu\mA
{ M~uMY+>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :-z&Y492
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F8;mYuA
nStartPos,nEndPos,i); 2Kjrw;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aX|g S\zx
fileSplitterFetch.start(); 1\/{#c
} OY:u',T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .}o~VT:!?Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0!pJ5q ,A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4Rx~s7l
nEndPos = " + nFileLength); rn;<HT
// fileSplitterFetch[nPos.length-1].start(); B`i$Wt<7
u t$c)_
a0PE^U
//等待子线程结束 h\(B#SN
//int count = 0; C,fY.CeI
//是否结束while循环 zX98c
boolean breakWhile = false; bl=ku<}@
vv+km+
2`EVdl7B]
while(!bStop) rvwa!YY}
{ ["u#{>(X
write_nPos(); "Ht'{&
Utility.sleep(500); +~N!9eMc
breakWhile = true; 30s; }
6ZcXS
zVw:7-
for(int i=0;i<nStartPos.length;i++) 3f"C!l]Xu
{ `{[RjM`
if(!fileSplitterFetch.bDownOver) uAUp5XP|Z
{ #.H}r6jqs
breakWhile = false; >p0KFU
break; R::zuv
} l-<`m#/v
} YlTaN,?j
if(breakWhile) TN\|fzj
break; \w%@?Qik
ziiwxx_
$#e1SS32
//count++; 7/aOsW"6
//if(count>4) &n:{x}Uc
// siteStop(); 3@_Elu
} zyFUl%
L0L2Ns
M/pMs 6
System.err.println("文件下载结束！"); 1'JD=
} :Wc_Utt
catch(Exception e){e.printStackTrace ();} I-kWS4
} uR$i48}
H;Ku w
Z+4D.bA
//获得文件长度 z=g$Exl
public long getFileSize() $=)gpPT
{ Su7bm1
int nFileLength = -1; ((bTwx
try{ '#.#$8l
URL url = new URL(siteInfoBean.getSSiteURL()); K\u_Ji]k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yf}xwpuLk
httpConnection.setRequestProperty("User-Agent","NetFox"); yCP4r6X0
nS9wb1Zl
u5+|Su
int responseCode=httpConnection.getResponseCode(); 69OF_/23
if(responseCode>=400) p*20-!{A
{ Z"y=sDO{
processErrorCode(responseCode); b?T
return -2; //-2 represent access is error H43MoC
} \+ 0k+B4a
5T?-zFMM
[0y$! f4
String sHeader; gE])!GMM3
z~{&}Em ~
k|xtr&1N.!
for(int i=1;;i++) ; )Eo7?]-
{ )Xtnk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @t*t+Vqw
//Utility.log(in.readLine()); ~}"]&%Q{J
sHeader=httpConnection.getHeaderFieldKey(i); 1:M@&1LYp
if(sHeader!=null) S DLvi!y
{ t#i,1aHA
if(sHeader.equals("Content-Length")) hA1-){aw3q
{ N?P%-/7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,|kDsR!
break; ,Lr<)p
} UVQ7L9%?f
} iyta;dw9
else U#&7p)4(
break; m P'^%TE
} o*rQP!8,oy
} hC <O`|lF
catch(IOException e){e.printStackTrace ();} $~;D9
catch(Exception e){e.printStackTrace ();} =#gEB#$x:
[`RX*OH2
QPtGdd
Utility.log(nFileLength); kOo~%kcQ'
U.!lTLjfLz
*+)AqKP\Kv
return nFileLength; T"7~AbgNU
} A][fLlpr
a^d8I
?L&|Uw+
//保存下载信息（文件指针位置） 03E4cYxt5
private void write_nPos() \;u@"
{ Rp7ntI:
try{ y\dEk:\)
output = new DataOutputStream(new FileOutputStream(tmpFile)); kHw_ S-
output.writeInt(nStartPos.length); X4l@woh%
for(int i=0;i<nStartPos.length;i++) z4M9M7)"
{ )WT>@
// output.writeLong(nPos); I$N8tn+E
output.writeLong(fileSplitterFetch.nStartPos); GaX[C<Wt
output.writeLong(fileSplitterFetch.nEndPos); ,C%eBna4Iq
} ./Q,
output.close(); e@:sR
} AKMm&(fh%
catch(IOException e){e.printStackTrace ();} b)(?qfXWP
catch(Exception e){e.printStackTrace ();} E|'h]NY
} sBrI}[oyx
V,rq0xW
3bnS W5
//读取保存的下载信息（文件指针位置） E4m`
private void read_nPos() Hx,0zS%>
{ F 8B#}%JE
try{ KM^ufF2[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V<k8N^
int nCount = input.readInt(); e[hcJz!D
nStartPos = new long[nCount]; lz1wO5%h
nEndPos = new long[nCount]; V5*OA??k<
for(int i=0;i<nStartPos.length;i++) o=0]el^A
{ 5mb]Q)f9-
nStartPos = input.readLong(); tHzZ@72B7
nEndPos = input.readLong(); pb~pN
} "etPT@gF
input.close(); 9K1oZ?)_z
} itC-4^
catch(IOException e){e.printStackTrace ();} h:9Zt0,
catch(Exception e){e.printStackTrace ();} )ZN|t?|
} 9-MUX^?u
CHz+814
o"*AtGR+"
private void processErrorCode(int nErrorCode) i>(e}<i
{ thhwN A
System.err.println("Error Code : " + nErrorCode); x&0vKo;
} fk&8]tK4
z*-2.}&U<
SJHr_bawd
//停止文件下载 [UH||qW
public void siteStop() N0r16# -g
{ 9g<7i
bStop = true; A,a.8!*}vd
for(int i=0;i<nStartPos.length;i++) 5k.oW=
fileSplitterFetch.splitterStop(); &G-!qxe
:\|SQKD
bD?VU<)3
} *6>.!&
} aeD;5VV
//负责部分文件的抓取 b}"N`,0dO
**FileSplitterFetch.java }R{ts
*/ sc}~8T
package NetFox; ;<ZLcTL
GaK-t*Q
rogT~G}q
import java.io.*; y]f"@9G#
import java.net.*; VcXq?f>\
B&n<M]7
c_4[e5z
public class FileSplitterFetch extends Thread { ^y<<>Y'I
xjKR R?
GU( _
String sURL; //File URL `)_dS&_\
long nStartPos; //File Snippet Start Position ?M\{&mlF
long nEndPos; //File Snippet End Position *=V~YF:Qb
int nThreadID; //Thread's ID # mV{#B=
boolean bDownOver = false; //Downing is over 9[.8cg*
boolean bStop = false; //Stop identical ,)vDeU
FileAccessI fileAccessI = null; //File Access interface _I:/ZF5
A\HxDIU
`ojoOB^L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u=`L)
{ \nPEyw,U
this.sURL = sURL; ~Vr.J}]J
this.nStartPos = nStart; )p<ExMIxd
this.nEndPos = nEnd; ~?K~L~f5
nThreadID = id; 0.8 2kl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }&wUr>=
} ^c9t'V`IWQ
CEX"D`
t.xxSU5~%
public void run() AP'*Nh@Ik(
{ I|^;B8[
while(nStartPos < nEndPos && !bStop) B><d9d
{ iKX-myCz
]&lY%"U$i
_./Sk|C
try{ [OC5l>
URL url = new URL(sURL); MkfBuW;)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); PHZ0P7
httpConnection.setRequestProperty("User-Agent","NetFox"); =THpdtL
String sProperty = "bytes="+nStartPos+"-"; fSK]|"c
httpConnection.setRequestProperty("RANGE",sProperty); pKpUXfQu
Utility.log(sProperty); X-K=!pET
wn/_}]T
L~lxXTG\
InputStream input = httpConnection.getInputStream(); >\KNM@'KI
//logResponseHead(httpConnection); u{['<r;I
RI(DXWM|h
9]f!'d!5
byte[] b = new byte[1024]; tX_R_]v3
int nRead; 0i!uUF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D1zBsi94D
{ p@xf^[50k
nStartPos += fileAccessI.write(b,0,nRead); _m5uDF?[
//if(nThreadID == 1) _Kl_61k
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Oo5w?+t
} `6~Aoe
"s0)rqf<
2$+bJJM
Utility.log("Thread " + nThreadID + " is over!"); WW4vn|0v
bDownOver = true; v%+:/m1
//nPos = fileAccessI.write (b,0,nRead); Br1&8L-|%
} 42G)~lun-d
catch(Exception e){e.printStackTrace ();} :XZU&Sr"
} tn(JC%?^
} ,)Me
MQ5R O;RY
T@2#6Tffo
//打印回应的头信息 #`CA8!j!!
public void logResponseHead(HttpURLConnection con) Z}mLLf E
{ q&s3wDl/
for(int i=1;;i++) ,(d)Qg
{ Wbr|_W
String header=con.getHeaderFieldKey(i); !t$'AoVBq
if(header!=null) r`W)0oxD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EofymAi%
Utility.log(header+" : "+con.getHeaderField(header)); >,gg5<F-E
else *W,]>v0%T
break; .}t~'*D
} uki#/GzaO
} x$5) ^ud?
UO0{):w>
iU$] {c2;A
public void splitterStop() {.?ZHy\Rk
{ *H"B _3<n
bStop = true; H?<N.Dq
} C'\- @/
k1w_[w[
6& e3Nt
} i2E)P x
{> eXR?s/
mn, =i
/* }zkHJxZgE
**FileAccess.java _<k\FU r
*//文件访问(定位，写) XewVcRo
package NetFox; g7}Gip}.>
import java.io.*; t3*wjQ3
=mS\i663
`Nz/Oh7
public class FileAccessI implements Serializable{ 4r>6G/b8*
")O%86_Q:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [Y|8\Ph`&
RandomAccessFile oSavedFile; ~ELNyI11
long nPos; Sj]T
!\nBh
6G1@smP
public FileAccessI() throws IOException B~]k#Ot)
{ d4u})
this("",0); w~(1%p/
} R)_%i<nq\
rID#`:Hl-|
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public FileAccessI(String sName,long nPos) throws IOException aZ2!i
{ d/PiiiFf,
oSavedFile = new RandomAccessFile(sName,"rw"); ]RPs|R?
this.nPos = nPos; |SoCRjuCPM
oSavedFile.seek(nPos); YLqGRE`W
} f\]sz?KY
0H6(EzN
}SX,^|eN
public synchronized int write(byte[] b,int nStart,int nLen) F<n3
{ pf1BN@ t
int n = -1; o|>'h$
try{ j/R[<47
oSavedFile.write(b,nStart,nLen); KC/=TSSXd.
n = nLen; r[2ILe
} m_.>C
catch(IOException e) \]</w5 Pi,
{ I KqQ>Z-q~
e.printStackTrace (); 4]yOF_8h
} dYT%
wG~`[>y (
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return n; Wi*.TWz3
} (zgW%{V@
W}m)cn3@
/M|262%
} tXoWwQD;Y
&,}j#3<
<vUbv
/* WlB
**SiteInfoBean.java GC?ON0g5s
*/ syWG'(>
package NetFox; Ir {OheJ
I%r{]-Obr-
>[9J?H
public class SiteInfoBean { a2dnbfSWa[
c#|raXGT
v/](yT
private String sSiteURL; //Site's URL W~zbm]
private String sFilePath; //Saved File's Path RZHd9v$
private String sFileName; //Saved File's Name '9S8}q
private int nSplitter; //Count of Splited Downloading File 7({]x*o*%
eIz<)-7:
I/&%]"[^u
public SiteInfoBean() T+*%?2>q"
{//nSplitter的缺省值为5 <QA6/Ef7
//default value of nSplitter is 5 PMNjn9d
this("","","",5); qT%FmX
} pnjXf.g"O
P,xKZ{(
&7`^i.fh)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #pb92kA'
{ .$qnZWcgG
sSiteURL= sURL; |2RC#]/-Y
sFilePath = sPath; jBgP$g
sFileName = sName; QWD'!)Zb
this.nSplitter = nSpiltter; _JHd9)[
eM$sv9?
fDT%!
} pimtiQqC
HkO7R `
znxnL,-
public String getSSiteURL() #:[t^}
{ qv]}$WU
return sSiteURL; vgsJeV`}I
} V!lZ\)
sejg&8
{@+Ty]e
public void setSSiteURL(String value) P(H8[,
{ YL]Z<%aKt
sSiteURL = value; Nd$W0YN:
} TygW0b 1
@6wFst\t
|y0(Q V
public String getSFilePath() .}O[dR
{ %kS(LlL+6
return sFilePath; U*22h` S
} rEB@$C^
y~q8pH1
,1[q^-9
public void setSFilePath(String value) -I&m:A$4*
{ 4)A#2
sFilePath = value; gDQ1?N'8{t
} nEJY5Bz$
)}"wesNo".
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public String getSFileName() .^h#_[dp
{ mj9 <%P
return sFileName; n[G&ksQI
} 0:9.;x9_
AaWs}M
P} 0%-JC
public void setSFileName(String value) u*Pibgd<
{ <Bw^!.jAF
sFileName = value; /SrCElabP
} a1_GIM0
yCVI\y\B
uVJDne,R
public int getNSplitter() NTe5
{ P:k>aHnW
return nSplitter; ^/\Of{OZ-
} -"=U?>(
VJickXA
v(ZYS']d2
public void setNSplitter(int nCount) {q`jDDM
{ kBD>-5Sn_T
nSplitter = nCount; 6L"%e!be6
} 05b_)&4R
} A8uVK5
G(p`1~xm
1~Oe=`{&
/* _kU:Z
**Utility.java &jslyQ#
*/ amOnqH-(
package NetFox; c'%-jG)\
a@@)6FM
~Y|*`C_)
public class Utility { @+Si?8\
]:4*L
PIu1+k.r?
public Utility() bpH^:fyLU`
{ p i %<Sy
Y2n!>[[.
= \'}g?
} m1B+31'>^
K/i*w<aPb7
//线程睡眠 3I)VHMC
public static void sleep(int nSecond) MZSy6v
{ eg(6^:z?f
try{ @D{KdyW
Thread.sleep(nSecond); x=b7':nQ
} =t9\^RIx)?
catch(Exception e) iV'k}rXC
{ iBF|&h(\
e.printStackTrace (); OSs&r$
} M?Dfu .t
} (.D~0a JU
ok!L.ac
//日志 . $BUw
public static void log(String sMsg) a%kQl^I4
{ s5CXwM6cx
System.err.println(sMsg); (7*%K&x
} 1_9<3,7
&dM. d!
yXSFjcoB
public static void log(int sMsg) w_.F' E
{ qh9Z50E9
System.err.println(sMsg); >/l? g5{
} 2oVSn"
} B"h#C!E
hQYL`Dni
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/* >AVVEv18
**TestMethod.java ;LcZ`1
*/ `[f*Zv w
package NetFox; U{2BVqM
[@VP?74
#.rdQ,)<
public class TestMethod { 8aK)#tNWN
S\:P-&dC
|iakz|])
public TestMethod() q!.byrod
{ ///xx/weblogic60b2_win.exe idLWe9gC
try{ - Ajo9H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g;pcZ9o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nV"~-On
SiteFileFetch fileFetch = new SiteFileFetch(bean); &XIt5<$~R
fileFetch.start(); zZL6z4g
} HVi'eNgo
catch(Exception e){e.printStackTrace ();} ck:T,F{}
KaPAa:Q
azCf
} CDsSrKhx
/sx@$cvW
YWe{juXSw
public static void main(String[] args) |n2qVR,
{ fz|cnU
new TestMethod(); 5x5@t :
} GzhYY"iif#
} 2^r<{0@n
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