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)); og<mFbqkq7
} C 7)w8y
for(int i=0;i<nEndPos.length-1;i++) (he cvJ
{ 7/nnl0u8
nEndPos = nStartPos[i+1]; $Cw> z^}u
} !e?g"5r{Bv
nEndPos[nEndPos.length-1] = nFileLength; t{n|!T&
} D7.|UG?G
} 6KuB<od
4<b=;8
f$vWi&(
//启动子线程 a[;TUc^I1F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bkfwsYZx
for(int i=0;i<nStartPos.length;i++) =~M%zdIXv
{ I^>m-M.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), II;fBcXF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), / 4P+
nStartPos,nEndPos,i); Gq_rZo(@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -F.A1{l[.
fileSplitterFetch.start(); '|mVY; i[
} UX3 ]cr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /,v>w,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wg<UCmfu!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YY~BNQn6d
nEndPos = " + nFileLength); \mRRx#-r%
// fileSplitterFetch[nPos.length-1].start(); n]$50_@
nA:\G":\y
J ik+t\A
//等待子线程结束 T=6fZ;7
//int count = 0; K?[*9Q'\
//是否结束while循环 >*#clf;@p
boolean breakWhile = false; WqX#T
i7g+8zd8d
HAa2q=
while(!bStop) bvY'=
{ !QK~l
write_nPos(); ;8z40cD
Utility.sleep(500); i[obQx S94
breakWhile = true; U40adP? a
t?JY@hT*
bvZTB<rA
for(int i=0;i<nStartPos.length;i++) rv>K0= t0
{ )NG{iD{_]
if(!fileSplitterFetch.bDownOver) !vNZ-}
{ 'BY{]{SL
breakWhile = false; Wez"E2J`
break; ?M'_L']N[
} t[Dg)adc
} ,VK! 3$;|
if(breakWhile) Ul@Jg
break; '\yp}r'u
0Y7b$~n'Y
VO"f=gFg
//count++; WR'm<u
//if(count>4) ub^v,S8O
// siteStop(); 3m1]Ia-9
} (x7AV$N
P} =eR
?U~}uG^
System.err.println("文件下载结束！"); q}Wd`>VDR
} 5r1{l%?
catch(Exception e){e.printStackTrace ();} 2p3ep,
} +^!;J/24
rG7S^,5o
mQ#E{{:H+
//获得文件长度 CS[[TzC=5
public long getFileSize() P$4h_dw
{ V'vDXzk\
int nFileLength = -1; B/#tR^R
try{ q0Rd^c
URL url = new URL(siteInfoBean.getSSiteURL()); OE,uw2uaT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !_{2\&
httpConnection.setRequestProperty("User-Agent","NetFox"); ('1k%`R%
&mebpEHUG7
ppcuMcR{
int responseCode=httpConnection.getResponseCode(); [5&zyIi
if(responseCode>=400) Q8:`;W
{ 1S!<D)n
processErrorCode(responseCode); hR;J#w
return -2; //-2 represent access is error Mv9q-SIc[
} ]KX _a1e
<a>\.d9#)7
$,+'|_0yM
String sHeader; b}P5*}$:9"
cp|&&q
![O@{/
for(int i=1;;i++) IEb"tsel
{ K*&?+_v :
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]V9z)uz
//Utility.log(in.readLine()); gemjLuf
sHeader=httpConnection.getHeaderFieldKey(i); RfPRCIo
if(sHeader!=null) I"*;fdm
{ }@Mx@ S
if(sHeader.equals("Content-Length")) (`0dO8
{ @d5G\1(%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z?~W]PWiZ
break; i*16kdI.
} lLuAZoH
} =6#tJgg8
else 2Z]<MiAxD
break; .HTX7mA3
} 9T*%CI
} Rg*zUfu5%o
catch(IOException e){e.printStackTrace ();} ?H9F"B$a
catch(Exception e){e.printStackTrace ();} G-FTyIP>'
r30t`o12i
*,9.Bx*
Utility.log(nFileLength); 2i);2>HLG
phIEz3Fu/
m.~&n!1W*`
return nFileLength; $mA+4ISK
} B7Um G)C
h-VpX6
q9n0bw^N
//保存下载信息（文件指针位置） 51oZw%os=
private void write_nPos() 5BKmp-m
{ y%T5"p$,
try{ {b@rQCre7
output = new DataOutputStream(new FileOutputStream(tmpFile)); amI$0
output.writeInt(nStartPos.length); &lYKi3}x
for(int i=0;i<nStartPos.length;i++) Zp|LCE"
{ "i$uV3d
// output.writeLong(nPos); }vOUf#^k
output.writeLong(fileSplitterFetch.nStartPos); _q([k_4h
output.writeLong(fileSplitterFetch.nEndPos); )Qve[O
} <@CBc:j0
output.close(); 9E{Bn#
} eK"B.q7
catch(IOException e){e.printStackTrace ();} Qi^MfHW
catch(Exception e){e.printStackTrace ();} Vy = fm
} ]y6`9p
fTi,S)F'
Xq&x<td
//读取保存的下载信息（文件指针位置） zE VJ
private void read_nPos() 8uME6]m i
{ @URLFMFi
try{ nbYkr*: "t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P=&Je?
int nCount = input.readInt(); *VT@
nStartPos = new long[nCount]; }I7/FqrD
nEndPos = new long[nCount]; ;??wLNdf-
for(int i=0;i<nStartPos.length;i++) Mj$dDtw
{ WNTm
nStartPos = input.readLong(); vx=I3o
nEndPos = input.readLong(); n5_r 3{
} pt8X.f,iA
input.close(); zx\N^R;Jq
} :>lica_
catch(IOException e){e.printStackTrace ();} v>Il#
catch(Exception e){e.printStackTrace ();} |dNtM^
} ZNPzQ:I@
/2oTqEqaV
vCwDE~
private void processErrorCode(int nErrorCode) ?,r bD1
{ "fLGXbNQ
System.err.println("Error Code : " + nErrorCode); [d!C6FT
} /qF7^9LtaY
O?@1</r^
{xt<`_R
//停止文件下载 yy?|q0
public void siteStop() ] K7>R0
{ ?Gl'-tV
bStop = true; EU,4qO
for(int i=0;i<nStartPos.length;i++) 6<H[1PI`,G
fileSplitterFetch.splitterStop(); e4NT
G*BM'^0+
e#k9}n^+
} <9bQAyL9
} c>K/f7
//负责部分文件的抓取 Xj$J}A@
**FileSplitterFetch.java |aN0|O2
*/ fDq, )~D
package NetFox; kETA3(h'
bi!4I<E>k
<Q=ES,M
import java.io.*; ^e8R43w:!
import java.net.*; 5h[u2&;G
p)tac*US
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public class FileSplitterFetch extends Thread { c}mJ6Pt
:LVM'c62c>
&+`l $h
String sURL; //File URL oO @6c%
long nStartPos; //File Snippet Start Position GT%V,OJ
long nEndPos; //File Snippet End Position MvY0?!v
int nThreadID; //Thread's ID U=XaI%ZM)
boolean bDownOver = false; //Downing is over *D<S \6=
boolean bStop = false; //Stop identical LF%1)x
FileAccessI fileAccessI = null; //File Access interface (W+9 u0Zq
*wp'`3y}
!U>"H8}dv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1s\10 hK1c
{ /db?ltb
this.sURL = sURL; ~1Tz[\H#R
this.nStartPos = nStart; T-&CAD3 ,O
this.nEndPos = nEnd; ~N[hY1}X[
nThreadID = id; |k&.1NkZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -7ct+3"J
} /_,~dt
j %TYyL-
=[{Pw8['
public void run() q22cp&gmX
{ Hh;w\)/%j
while(nStartPos < nEndPos && !bStop) }(E6:h;}~
{ '! 1ts@
;~]&$2sk
DHt 8 f
try{ zwU8iVDe
URL url = new URL(sURL); (53dl(L?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *"fg@B5
httpConnection.setRequestProperty("User-Agent","NetFox"); @+1E|4L1vf
String sProperty = "bytes="+nStartPos+"-"; .ET;wK
httpConnection.setRequestProperty("RANGE",sProperty); d@At-Z~M
Utility.log(sProperty); ![Ip)X OG
}C*o;'o5G
K- }k-S
InputStream input = httpConnection.getInputStream(); P+}qaup
//logResponseHead(httpConnection); q'(WIv@
!+uMH!
'dWJ#9C
byte[] b = new byte[1024]; #]lUJ &M}e
int nRead; &K>]!yn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X""'}X|O
{ oTI*mGR1Z
nStartPos += fileAccessI.write(b,0,nRead); 7v,>sX
//if(nThreadID == 1) F5 LQgK-z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iqy}|xAU
} +crAkb}i
`zzX2R Je
mApn(&
Utility.log("Thread " + nThreadID + " is over!"); x(]s#D!)
bDownOver = true; ~;eWQwD
//nPos = fileAccessI.write (b,0,nRead); iLmU|jdE
} jLQjv
catch(Exception e){e.printStackTrace ();} e_1mO 5z
} 1 9 k$)m
} n[4Nu`E9
CPVKz
c6c^9*,V
//打印回应的头信息 OM4s.BLY
public void logResponseHead(HttpURLConnection con) /kw4":{]
{ yN>"r2
for(int i=1;;i++) K,IOD t
{ N7oMtlvL[w
String header=con.getHeaderFieldKey(i); J~_p2TZJ\3
if(header!=null) J.<eX=<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l*v([@A\
Utility.log(header+" : "+con.getHeaderField(header)); =rBFMTllM
else 7Ck;LF}>0
break; =\XAD+
} 'oT}jI
} e-e{-pB6
5)nv
}qKeX4\-
public void splitterStop() >`{i[60r
{ Tby+Pd;
bStop = true; (VOKa
} mlVv3mVyR<
@\"*Z&]8z0
chd${ j
} }MIH{CMH
6\TstY3
)F~>
/* [CUJA
**FileAccess.java ?1N0+OW
*//文件访问(定位，写) y:42H tS
package NetFox; '^/E2+
import java.io.*; Bw_Ih|y,w
]~K&mNo
)K?GAj]Pq
public class FileAccessI implements Serializable{ `PW=_f={
he+[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9Np0<e3p
RandomAccessFile oSavedFile; |wLQ)y*
long nPos; cbwzT0
*$cp"
:jUuw:\
public FileAccessI() throws IOException YAPD7hA
{ /GXO2zO
this("",0); 9{TOFjsF
} ReE3742@
3?%kawO&
<>e<Xd:77{
public FileAccessI(String sName,long nPos) throws IOException ks r5P~
{ #!5Nbe
oSavedFile = new RandomAccessFile(sName,"rw"); e`~q;?:
this.nPos = nPos; WuNu}Ibl}m
oSavedFile.seek(nPos); Dw#&x/G
} e{}o:r
b?Jm)
-$0S#/)Z
public synchronized int write(byte[] b,int nStart,int nLen) <Z__Q
{ ZH}NlEn
int n = -1; sY6'y'a95
try{ h4qR\LX
oSavedFile.write(b,nStart,nLen); |M?HdxPa
n = nLen; F0JFx$AoD
} J6%op{7/
catch(IOException e) 1(?J>{-lw
{ d+;wDu
e.printStackTrace (); Q&#:M>!|
} Kje+Niz7
amSyGQ2
i3"sArP"|
return n; g.]'0)DMW
} TkBBHg;
;MMFF{
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} UZ!hk*PF
bVx]r[
IYO,/ kbf
/* V[mQ;:=
**SiteInfoBean.java etoE$2c
*/ iN*>Z(b"
package NetFox; PGKXzp'
1A)~Y
uUe\[-~
public class SiteInfoBean { G8s`<:9*
0/6&2
mqHt%RX
private String sSiteURL; //Site's URL kYs|")isj
private String sFilePath; //Saved File's Path AWDjj\Q4
private String sFileName; //Saved File's Name _tk5?9Ykn
private int nSplitter; //Count of Splited Downloading File XZInu5(
cP1jw%3P
k:TfE6JZ
public SiteInfoBean() SRTpE,
{//nSplitter的缺省值为5 [:QMnJ
//default value of nSplitter is 5 U.aa iX7
this("","","",5); *X\c $=*
} W.|6$hRl)
injmP9ed
)^\='(s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;Kf|a}m-
{ vdm?d/0(^
sSiteURL= sURL; sb @hGS
sFilePath = sPath; JB+pFBeY
sFileName = sName; 9NP l]iA)
this.nSplitter = nSpiltter; Tv$7aVi!
R`Lm"5w
j;v%4G
} $3TTHS o
i .N1Cvp&
!_9$[Oq~
public String getSSiteURL() )DmiN^:
{ B@]7eVo
return sSiteURL; `I8^QcP
} ymZ/(:3_
{+2cRr.
tTGK25&
public void setSSiteURL(String value) >bN~p
{ <L~xR5
sSiteURL = value; sAoM=n}!
} zy[=OX+
9i}D6te
(U_Q7hja?
public String getSFilePath() bUN,P"
{ @q/1m~t
return sFilePath; pK9^WT@
} 2?T:RB}
X u):.0I
dz|*n'd
public void setSFilePath(String value) pq3 A%|
{ wzPw;xuG
sFilePath = value; igrog
} X|`,AKJit
"Y]ZPFh#.
EQ7n'Wqq
public String getSFileName() 5j,qAay9
{ CS\tCw\Y
return sFileName; C94@YWs
} nV3 7` I
Tr0V6TS7
&H&P)Px*_
public void setSFileName(String value) !>< %\K
{ r`&|)Hx
sFileName = value; yim$y,=d
} 50ew/fZj|
aNC,ccm
:bRR(sP
public int getNSplitter() Kk>qgi$
{ 5\0.[W{^
return nSplitter; _IV@^v
} )v=G}j^
cXcx_-
(VaN\+I:T
public void setNSplitter(int nCount) RVnyl`s
{ SMO%sZ]
nSplitter = nCount; 2 dD<]
} AdEbyL
} @JEmybu
CQHp4_
PdH`_/6
/* 4spaw?j
**Utility.java nRB>[lG
*/ 4l}M i
package NetFox; BZ+ mO
As~p1%nok
P5}[*k%DQw
public class Utility { < }wAP_y
n [Xzo}
Ik5jwfz
public Utility() 5o| !f
{ wUCDJY:,1
:"P hkR
O)xEF~DaD
} GHJ=-9{YL
< mK
//线程睡眠 '?G[T28
public static void sleep(int nSecond) ,(0XsBL
{ [k~+(.2I
try{ ]Ec[")"kT
Thread.sleep(nSecond); =x0"6gTz>
} !@Sf>DM"
catch(Exception e) r\n h.}s
{ VuMDV6^Z
e.printStackTrace (); sRyw\v-=P
} 2Z`$
} "56?/ jF
+Bq}>
//日志 ]X: rby$
public static void log(String sMsg) R_Gq8t$
{ #1't"R+3M
System.err.println(sMsg); cCh5Jl@Z
} an=+6lIl
lDJd#U'V
a^XTW7]r
public static void log(int sMsg) ;Co[y=Z
{ wEfz2Eq
System.err.println(sMsg); C*s0r;
} rF'^w56
} R'9@A\7#
IN|i)?rh
,-7/]h,l
/* c_z/At;4
**TestMethod.java L_gsG|xX
*/ aC,vh1")F
package NetFox; 0"kE^=
QK?2E
?St=7a(D
public class TestMethod { )qyx|D
~f=6?5.wa
dx13vZ3[U
public TestMethod() XW~ BEa
{ ///xx/weblogic60b2_win.exe tT* W5
try{ YZBzv2'\x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 64!ame}n+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W\>^[c/
SiteFileFetch fileFetch = new SiteFileFetch(bean); HhWwc#B
fileFetch.start(); }r~v,KDb
} ll(e,9.D
catch(Exception e){e.printStackTrace ();} mF*?e/
/h7>Z9T
Y*kh$E%<#
} qXU:A-IdIl
Z9"{f)T
\2R`q*a+
public static void main(String[] args) b 5F4+
{ 5xMA~I0c
new TestMethod(); V<HOSB7
} AU\xNF3
} t*Vao
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