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)); Gc'M[9Mh
} lH6fvz
for(int i=0;i<nEndPos.length-1;i++) Y&5.9 s@'
{ YQ7@D]#
nEndPos = nStartPos[i+1]; l sr?b
} +(&|uq^
nEndPos[nEndPos.length-1] = nFileLength; T pD;
} *{|$FQnR>(
} $ser+Jt=
ceG&,a$\
*QE"K2\5
//启动子线程 *gDl~qNRoS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <h@]Ri
for(int i=0;i<nStartPos.length;i++) ^Q\XGl
{ G,|KL" H6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CdL.?^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ot }6D
nStartPos,nEndPos,i); #q;z8 @
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |z*>ixK
fileSplitterFetch.start(); 3ev-Iqz
} (hN?:q?'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zSXA=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ha)np
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $w/E9EJ)3A
nEndPos = " + nFileLength); mX;H((
// fileSplitterFetch[nPos.length-1].start(); Cfv]VQQE
P#;Th8k{K2
1'fb @vO
//等待子线程结束 y42#n
//int count = 0; Du!._
//是否结束while循环 %Kl(>{N
boolean breakWhile = false; /[{auUxSX
+GeWg` \=
`*k@4.J{
while(!bStop) 95LyYg
{ \0&SI1Yp
write_nPos(); jT-<IJh!o
Utility.sleep(500); 9yL6W'B!
breakWhile = true; " #v%36U
oM-[B h]A
OaaH$B
for(int i=0;i<nStartPos.length;i++) D5L{T+}Oi%
{ i*CnoQH
if(!fileSplitterFetch.bDownOver) 5\'AD^{
{ d.AC%&W
breakWhile = false; esI'"hVJ
break; 7&|6KN}c
} <u0,Fp
} 4K7{f+T
if(breakWhile) cz(G]{N
break; 2Wl{Br.
wE6A 7\k%
328L)BmW
//count++; oKa>.e7.
//if(count>4) }#/lN
// siteStop(); H=<LutnZ
} F#|Z# Mu
RRzP*A%=
hB>^'6h+
System.err.println("文件下载结束！"); T1zi0fa'
} H1&RI4XC
catch(Exception e){e.printStackTrace ();} [.-a$J[4+F
} ag;dc
FN\GE\H
pkk4h2Ah
//获得文件长度 "dtlME{Bx
public long getFileSize() (a#pvEY
{ 0Oap39
int nFileLength = -1; Y;_T=L
try{ -Qb0:]sV#
URL url = new URL(siteInfoBean.getSSiteURL()); >lLo4M 3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $[z<oN_Q
httpConnection.setRequestProperty("User-Agent","NetFox"); Yqj+hC6>,
<5IQc[3]aP
(Ilsk{aB;A
int responseCode=httpConnection.getResponseCode(); bVK$.*,
if(responseCode>=400) }_%P6
{ ir&.Z5=
processErrorCode(responseCode); "DpKrVuG
return -2; //-2 represent access is error yU_9a[$V
} L~&" aF/b
,LUTHWEo"I
7I >J$"
String sHeader; @i1q]0
gtYRV*^q
"8/dD]=f^a
for(int i=1;;i++) !y*oF{RZ
{ U^?= 0+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J?D\$u:
//Utility.log(in.readLine()); 1;&T^Gdj
sHeader=httpConnection.getHeaderFieldKey(i); tX?J@+
if(sHeader!=null) e U;jP]FA
{ XwPx9+b6j
if(sHeader.equals("Content-Length")) 8Q(8b@ZO,
{ P {H{UKs#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Le@? /
break; 3.),bm
} 4f {+pf^R
} c0[k T
else 6Xa.0(h
break; ^73=7PZ
} ~:Mm<*lL%
} }N,>A-P
catch(IOException e){e.printStackTrace ();} e{!vNJ0`
catch(Exception e){e.printStackTrace ();} VMHC/jlX@r
;J=:IEk
R|Y~u*D
Utility.log(nFileLength); :-Wv>V\t
8&.-]{Z
7>,rvW:]
return nFileLength; 1VLLo~L%
} .'lN4x
&HL{LnLP@/
Ef,Cd[]b
//保存下载信息（文件指针位置） >FF1)~
private void write_nPos() [hHG.
{ jVYH;B%%z
try{ .$wLLE^*
output = new DataOutputStream(new FileOutputStream(tmpFile)); hk;bk?:m
output.writeInt(nStartPos.length); *h:kmT
for(int i=0;i<nStartPos.length;i++) 3_zSp.E\l
{ D9o*8h2$
// output.writeLong(nPos); :Tb7r6
output.writeLong(fileSplitterFetch.nStartPos); _6rKC*Pe1
output.writeLong(fileSplitterFetch.nEndPos); bU+9Gi@v
} h=[-Er'B
output.close(); xa#gWIP*
} QJSr:dP4dG
catch(IOException e){e.printStackTrace ();} (\vXA4Oa,
catch(Exception e){e.printStackTrace ();} } yq
} euZI`*0
^'W%X
x+^Vg3 q
//读取保存的下载信息（文件指针位置） 4_Y!elH)
private void read_nPos() 5;Ia$lm=y
{ N-QCfDao
try{ `~nCbUUee
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =]b9X7}
int nCount = input.readInt(); 61:9(*4~!F
nStartPos = new long[nCount]; C3.=GRg~l
nEndPos = new long[nCount]; }n[Bq#
for(int i=0;i<nStartPos.length;i++) ,` o+ ?
{ U~/ID
nStartPos = input.readLong(); kl<g;3
nEndPos = input.readLong(); ) ,Npv3(
} ?Aw3lH#:
input.close(); 0N5bPb
} !Uy>eji}
catch(IOException e){e.printStackTrace ();} e1^l.>2d6
catch(Exception e){e.printStackTrace ();} uV77E*+7\
} c&e0OV\m
^Y 7U1I
ZNL5({lv
private void processErrorCode(int nErrorCode) s=U\_koyH
{ ke6n/ h5`
System.err.println("Error Code : " + nErrorCode); g;G5 r&T
} Q|//Z
;)|nkI
!*bdG(pK
//停止文件下载 oHsP?%U
public void siteStop() `M]BhW)
{ PL@7KDQ
bStop = true; 2sun=3qb
for(int i=0;i<nStartPos.length;i++) NCDxcz;Gb
fileSplitterFetch.splitterStop(); D|TR!
b1)\Zi
v,0<9!'v
} 7d9Z/J@>
} (hsZ
//负责部分文件的抓取 0WXVc
**FileSplitterFetch.java **HrWM%?8o
*/ E9R]sXf8
package NetFox; L*^ V5^-
iT$d;5_pU
vZk9gGjk
import java.io.*; `^e*T'UPl
import java.net.*; Wr#~GFg
?(Bl~?zD
3+zzi
public class FileSplitterFetch extends Thread { 9b%j.Q-W
Tk](eQsy.v
PUKVn+h
String sURL; //File URL d?}hCo=/Xq
long nStartPos; //File Snippet Start Position #ovM(Mld
long nEndPos; //File Snippet End Position ;@4sd%L8V
int nThreadID; //Thread's ID UN(3i(d
boolean bDownOver = false; //Downing is over )Ga8`t"
boolean bStop = false; //Stop identical PW)8aLU
FileAccessI fileAccessI = null; //File Access interface =mLeMk/7 w
.hne)K%={y
hgwn> p:S#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oG\>--
{ ^'YHJEK
this.sURL = sURL; r0uJ$/!
this.nStartPos = nStart; |0]YA
this.nEndPos = nEnd; 1tyNRoET
nThreadID = id; rXDJ:NP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;-Ado8
} `u=oeM:
Wl TpX`
WG\Q5k4Ba
public void run() 07Y_^d
{ X TM$a9)
while(nStartPos < nEndPos && !bStop) nF|Oy0
{ 4+I 3+a"
<M305BH
B G5X_s0/
try{ "$P'Wv
URL url = new URL(sURL); %2YN,a4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v^\JWPR/
httpConnection.setRequestProperty("User-Agent","NetFox"); DZ2Fl>7
String sProperty = "bytes="+nStartPos+"-"; '}CN?f|.
httpConnection.setRequestProperty("RANGE",sProperty); 4v>o%
Utility.log(sProperty); 1yJ75/
SdSgn|S
bq: [Nj
InputStream input = httpConnection.getInputStream(); ,zoB0([
//logResponseHead(httpConnection); I}_;A<U
/} a_8iM\
0}D-KvjyP
byte[] b = new byte[1024]; 4uPH
int nRead; H7}g!n?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L9$&-A9ix
{ T?#s'd
nStartPos += fileAccessI.write(b,0,nRead); nfa_8
//if(nThreadID == 1) '(TmV#3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?N`qLGRm
} cB<O.@
|zh +
|+u+)C
Utility.log("Thread " + nThreadID + " is over!"); ot0U-G(
bDownOver = true; ovbEmb
//nPos = fileAccessI.write (b,0,nRead); +\srZ<67
} 3jXR"@Z-
catch(Exception e){e.printStackTrace ();} L7<+LA)s0
} e|JIrOnc
} e) ]RA?bF
pbPz$Y
G~S))p
//打印回应的头信息 }\DAg'e)
public void logResponseHead(HttpURLConnection con) ,!r@9T
{ *|^,DGfQ6
for(int i=1;;i++) ;}UzJe ,S
{ L,WkJe3
String header=con.getHeaderFieldKey(i); gU+ss
if(header!=null) 1z3]PA!R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \FVNXUMU
Utility.log(header+" : "+con.getHeaderField(header)); B#QL M^
else b]"2VN
break; }#&~w0P
} sbgJw
} ~};]k}
)=y.^@UT@
$,.3&zsy
public void splitterStop() O/(3 87=U
{ k{_1r;
bStop = true; 0u>yT?jP
} +)?,{eE|
)dqR<)
c5<kbe
} 7&h\l6}Yh
hN[X 1*
*B%y`cj|
/* zf`5>h|
**FileAccess.java -Sx0qi'%
*//文件访问(定位，写) 1]Gf)|
package NetFox; o T:j:n
import java.io.*; 1k$2LQ
eU`;L[
q)NXyy4BT
public class FileAccessI implements Serializable{ -!@H["
jiqi!*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WUzSlZq
RandomAccessFile oSavedFile; hK Fk$A
long nPos; bAN10U
mlD%d!.
15o9CaQw4"
public FileAccessI() throws IOException :DDO=
{ y:~eU
this("",0); ,|6Y\L
} oN_S}o
#,t2*tM
u$apH{
public FileAccessI(String sName,long nPos) throws IOException %B[YtWqm`/
{ :wFb5"
oSavedFile = new RandomAccessFile(sName,"rw"); fdN45in=>
this.nPos = nPos; "&@gX_%
oSavedFile.seek(nPos); j[_t6Z
} dUI3erO
Rk}\)r\
mluW=fE
public synchronized int write(byte[] b,int nStart,int nLen) p 7 ,f6kG
{ 3gC\{y!8
int n = -1; C\y[&egww
try{ 2=jd;2~
oSavedFile.write(b,nStart,nLen); kZJt~}
n = nLen; eH ;Wfs2f
} o^8*aH)I>Y
catch(IOException e) 4 U3C~J
{ Tw2Xe S
e.printStackTrace (); =g/4{IL%
} :8](&B68gE
@m5O{[euj<
bjuYA/w<
return n; r5D jCV"
} <9=zP/Q
X'YfjbGo
n>u.3wL
} wYZye^7
W/b"a?wE{
s.f`.o
/* d&/^34gn
**SiteInfoBean.java )C'G2RV
*/ ` 52%XI
package NetFox; =9kj? u~
]\[m=0K
jn.R.}TT
public class SiteInfoBean { d1UVvyH
P h9Hg'
oxUE79
private String sSiteURL; //Site's URL &r&;<Q
private String sFilePath; //Saved File's Path V*~1,6N[
private String sFileName; //Saved File's Name ,h3269$J
private int nSplitter; //Count of Splited Downloading File J@oEV=L
jVLY!7Z4
='7er.~\
public SiteInfoBean() K#_~ !C4L
{//nSplitter的缺省值为5 :&xz5c`"04
//default value of nSplitter is 5 83mlZ1jQz
this("","","",5); 6\; 4 4,3
} ;M%oQ>].[
u)<Ysx8G
N!tpzHXw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jjJc1p0
{ $KoPGgC[
sSiteURL= sURL; lc\>DH\n6
sFilePath = sPath; ;n%]*v
sFileName = sName; TX<e_[$\
this.nSplitter = nSpiltter; ;b, -$A
2z'+1+B'
/X(@|tk:
} 1"8Z y6t
N BV}4
*ah>-}-
public String getSSiteURL() v_y!Oh?EG
{ ^L>MZA ?
return sSiteURL; #Tr;JAzVjG
} ygmv_YLjm
k! J4Z${k
eXj\DjttG}
public void setSSiteURL(String value) CBiU#h q
{ 0_YxZS\
sSiteURL = value; BP)q6?Mz
} 9oZ} h&
@5{.K/s
1Z^`l6|2
public String getSFilePath() 4M;sD;3
{ J!21`M-Ue
return sFilePath; i /O1vU#
} [W^6u7~
Y|{r vBKjf
-ET*M<
public void setSFilePath(String value) $=e&q
{ u=p ;A1oy
sFilePath = value; ]_^"|RJ
} aukk|/3Ih
w.4u=e >Z4
\zk?$'d
public String getSFileName() :FX'[7;p
{ +-Z"H)
return sFileName; ,pQ'w7
} MgJ%26TZ
3a'Rs{qxn
h(C#\{V
public void setSFileName(String value) :zizca4
{ =]_d pEEQ
sFileName = value; mQwk!* U
} viW~'}^k7
"D ts*
Wrf^O2
public int getNSplitter() _&k'j)rg
{ 4A\BGD*5
return nSplitter; U^E
} p9FA_(`^
)LXoey!aZ
v`[Tl
public void setNSplitter(int nCount) %v?jG(o
{ AijPN
nSplitter = nCount; "E@NZ*"u
} [ 4?cM\_u@
} Uv @!i0W
9%p7B~}E
O:oU`vE
/* .u&&H_ UmE
**Utility.java d1srV`
*/ "_ PH"W
package NetFox; !SLP8|Cd
^@|<'g.R-
>< <$
public class Utility { <GL}1W"Ay
ql#{=oGDnA
>,w\lf9
public Utility() ?6gDbE%
{ !(MA5L-
Z^/z
1S*8v7
} w>NZRP_3
?/`C~e<J
//线程睡眠 R`Ys;g/!
public static void sleep(int nSecond) <;$Sa's,LE
{ ,_"7|z wb
try{ ~6@c]:
Thread.sleep(nSecond); D-TNFYYy2
} 1=9qAp;?o
catch(Exception e) ! /|0:QQi
{ #hy5c,}>
e.printStackTrace (); ugIm:bg&
} 38x[Ad4%
} _Ep{|]:gw
xWenKY,
//日志 }AMYU>YE=
public static void log(String sMsg) }<5\O*kX4
{ yBYuDfeZ
System.err.println(sMsg); Xhq? 7P$3
} 7`uA
X <ba|(
7.lK$J:
public static void log(int sMsg) 8 7|8eU2:k
{ O" X!S_R
System.err.println(sMsg); c"f-$^<
} 7(A G]
} I&'S2=s
KV^:sxU
^-e3=&
/* ~WYE"(
**TestMethod.java 75hFyh;u
*/ .v #0cQX+.
package NetFox; 8T>3@kF
y]QQvCJr3d
|*]X\UE
public class TestMethod { ,%)WT>
&;NNUT>Q
d!}jdt5%
public TestMethod() xVHQ[I%
{ ///xx/weblogic60b2_win.exe eu}:Wg2
try{ i h`y0(<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7)8rc(58
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); np'M4^E;
SiteFileFetch fileFetch = new SiteFileFetch(bean); w{YtTZp3
fileFetch.start(); ;H m-,W
} &geOFe}R
catch(Exception e){e.printStackTrace ();} 5H'b4Cyi`
(04j4teE
Ru9pb~K
} m5'__<
2kp|zX(
:uT fhr
public static void main(String[] args) T_(e(5
{ Fu1|b2B-x
new TestMethod(); XqE55Jclp
} TeGLAt
} 6bRQL}[
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