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)); 2st3
} Vi|#@tC'
for(int i=0;i<nEndPos.length-1;i++) wb ;xRP"w
{ (^>J&[=
nEndPos = nStartPos[i+1]; #[[ en
} PQE=D0
nEndPos[nEndPos.length-1] = nFileLength; JlJ a #
} 7uk[Oy<_
} aDN`6[
y>ktcuML
IAyp2
//启动子线程 !p/goqT~dY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A":T1s
for(int i=0;i<nStartPos.length;i++) -F3-{E
{ dQG=G%W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f?)-}\[IR{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uEx-]F
nStartPos,nEndPos,i); GKeU%x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2>59q$|
fileSplitterFetch.start(); -ze J#B)C
} !TcJ)0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -7|H}!DFT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (QiAisE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VS|2|n1<6
nEndPos = " + nFileLength); $NO&YLS@
// fileSplitterFetch[nPos.length-1].start(); \^1E4C\":
@KUWxFak
L4l!96]a
//等待子线程结束 #,v{Ihn
//int count = 0; 4`=mu}Y2
//是否结束while循环 I*^Ta{j[
boolean breakWhile = false; U`s{Jm
W!(LF7_!
XB5DPx
while(!bStop) )WFr</z5bA
{ 8a"%0d#
write_nPos(); J?$,c4;W2
Utility.sleep(500); ,v}k{( 16{
breakWhile = true; ?Ss!e$jf
K~EmD9
pmYHUj #
for(int i=0;i<nStartPos.length;i++) 6-ils3&
{ S0W||#Pr
if(!fileSplitterFetch.bDownOver) f`66h M[
{ H" 7u7l
breakWhile = false; FXU8[j0P_G
break; W=4FFl[
} 1m0c|ckb
} @9|hMo
if(breakWhile) U,1-A=Og{o
break; I1&aM}y{G
oe~b}:
w@fi{H(R
//count++; 7E!5G2XX~~
//if(count>4) Ilm^G}GB
// siteStop(); Ny)X+2Ae
} lqpp)Cq
BING{ew
jmW7)jT8:
System.err.println("文件下载结束！"); sdmT
} ENY+^7
catch(Exception e){e.printStackTrace ();} C$)onk
} 8DaL,bi*.
'H<\x
\xoP)Ub>
//获得文件长度 "" ZQ/t\
public long getFileSize() }*"p?L^p{
{ m&yJzMW|
int nFileLength = -1; Jxm.cC5z.
try{ y"wShAR
URL url = new URL(siteInfoBean.getSSiteURL()); BIL Lq8)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Hu3>4<
httpConnection.setRequestProperty("User-Agent","NetFox"); c~ V*:$F
M\Kx'N
v/=}B(TDF
int responseCode=httpConnection.getResponseCode(); Owk|@6!
if(responseCode>=400) <Q?F?.^e
{ >[*qf9$
processErrorCode(responseCode); (dSL7nel;L
return -2; //-2 represent access is error 0{R=9wcc
} ,zY$8y]
;4~hB
cYt!n5w~W
String sHeader; ]OzUGXxo~
B^9j@3Ux
"'\$ g[k
for(int i=1;;i++) \)|hogI|f
{ 4{`{WI{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~e@z;]CiY
//Utility.log(in.readLine()); [cp+i^f
sHeader=httpConnection.getHeaderFieldKey(i); u.Dz~$T
if(sHeader!=null) DR<9#RRD
{ | %Vh`HT
if(sHeader.equals("Content-Length")) d>C$+v>
{ 7Jho}5J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '."ed%=MC
break; @sC`!Rmy'-
} kW&TJP+5*
} 3:i@II
else @I!0-OjL
break; b1?'gn~
} 0:Ol7
} \P`hq^;
catch(IOException e){e.printStackTrace ();} s!7y
catch(Exception e){e.printStackTrace ();} /s}}&u/
@J`"[%U
'1s0D]
Utility.log(nFileLength); "1M[5\Ax
'SF<_aS(
j eP
return nFileLength; hZ
} D!IY&H,wo
wDe& 1(T^
~FG]wNgS
//保存下载信息（文件指针位置） ut7zVp<"
private void write_nPos() 81 sG
{ |_@>*Vmg
try{ HCC#j9UN6
output = new DataOutputStream(new FileOutputStream(tmpFile)); A{D];pE`
output.writeInt(nStartPos.length); }?Ai87-{
for(int i=0;i<nStartPos.length;i++) _>X+ZlpU:
{ UrEs4R1#
// output.writeLong(nPos); Gu\q%'I
output.writeLong(fileSplitterFetch.nStartPos); [:SWi1cK2
output.writeLong(fileSplitterFetch.nEndPos); 5taT5?n2
} l)l^[2
output.close(); ^sLdAC
} -4{<=y?"a
catch(IOException e){e.printStackTrace ();} vuY~_
catch(Exception e){e.printStackTrace ();} m`^q <sj
} P:MT*ra*,
8>in_h9
>jc [nk
//读取保存的下载信息（文件指针位置） Q:d]imw!O
private void read_nPos() ,M ^<CJ
{ Uf;^%*P4
try{ 9 X`Sm}i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =R$u[~Xl2X
int nCount = input.readInt(); :emiQ
nStartPos = new long[nCount]; |"CZT#
nEndPos = new long[nCount]; = x)-u8P
for(int i=0;i<nStartPos.length;i++) EaY?aAuS:
{ 0rs"o-s<
nStartPos = input.readLong(); ]:k/Y$O2
nEndPos = input.readLong(); `Cynj+PCe
} .~~T\rmI
input.close(); c2 C8g1n
} Pw`8Wj
catch(IOException e){e.printStackTrace ();} =|y9UlsD
catch(Exception e){e.printStackTrace ();} h_,i&d@(
} (2E\p
">,|V-H
+.b,AqJ/
private void processErrorCode(int nErrorCode) aP@N)"
{ >rmqBDKaQ
System.err.println("Error Code : " + nErrorCode); 9ZsVy
} fW1CFRHH
J$w<$5UY
z3m85F%dR
//停止文件下载 SBk4_J/_
public void siteStop() ?(F6#"/E
{ goOCu
bStop = true; Em !/a$
for(int i=0;i<nStartPos.length;i++) Zbt.t]N
fileSplitterFetch.splitterStop(); g63(E,;;J
m6\E$;`
lc1(t:"[
} Q}K"24`=
} ^Hnb}L
//负责部分文件的抓取 0#s"e}@v
**FileSplitterFetch.java S8wLmd>
*/ :B5Fdp3
package NetFox; dI@(<R
gpvYb7Of0
H.|#c^I
import java.io.*; %G/hD
import java.net.*; +-U- D?-
Kp~VS<3
SpLzm A
public class FileSplitterFetch extends Thread { rv^@,8vq
n&;85IF1
TA`1U;c{n
String sURL; //File URL HIR~"It$
long nStartPos; //File Snippet Start Position bz2ztH9 n
long nEndPos; //File Snippet End Position n,V[eW#m'L
int nThreadID; //Thread's ID FaQe_;
boolean bDownOver = false; //Downing is over 2~1SQ.Q<RY
boolean bStop = false; //Stop identical y^,1a[U.
FileAccessI fileAccessI = null; //File Access interface ]}-7_n#cC
,c$_t+
kHghPn?8]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RXpw!
{ QQ*hCyw!
this.sURL = sURL; ug!s7fo^
this.nStartPos = nStart; nwB_8mN|
this.nEndPos = nEnd; mPtZO*Fc
nThreadID = id; z0p*Z&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "3)C'WlEy/
} B:;pvW]
I {S;L
~q@|l3?$
public void run() 7a=gH2]&
{ /7nb,!~~l
while(nStartPos < nEndPos && !bStop) W#4 7h7M
{ G7`ko1-
J{p1|+h%
7 S#J>*
try{ (>UZ<2GPL
URL url = new URL(sURL); N ,'GN[s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @w#-aGJO
httpConnection.setRequestProperty("User-Agent","NetFox"); xaq-.IQAM$
String sProperty = "bytes="+nStartPos+"-"; lk^Ol&6
httpConnection.setRequestProperty("RANGE",sProperty); ??-[eB.
Utility.log(sProperty); ?>D+ge
fnjPSts0
P_dCR
InputStream input = httpConnection.getInputStream(); V%7WUq
//logResponseHead(httpConnection); ?mwt~_s9
=t#llgi~
o lR?n(v
byte[] b = new byte[1024]; {NmWQyEv
int nRead; \+oQd=K@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '1P2$#
{ 4x=v?g&
nStartPos += fileAccessI.write(b,0,nRead); >\-hO&%_
//if(nThreadID == 1) >a!/QMh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h0*!;Z7
} Go`vfm"S
*.ll<p+(-
er("wtM
Utility.log("Thread " + nThreadID + " is over!"); |k )=0mCz
bDownOver = true; s[RAHU
//nPos = fileAccessI.write (b,0,nRead); ;V:i!u u
} {g'(~ qv
catch(Exception e){e.printStackTrace ();} |{z:IQLv
} .wEd"A&j
} jnkR}wAA
6C1#/
zq3\}9
//打印回应的头信息 -V*R\,>
public void logResponseHead(HttpURLConnection con) .Yamc#A-
{ t>L2
for(int i=1;;i++) fbyd"(V8r
{ oM X
String header=con.getHeaderFieldKey(i); S*,17+6dV
if(header!=null) NJ%P/\ C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aj-Km`5r}
Utility.log(header+" : "+con.getHeaderField(header)); z 4e7PW|
else rX U
break; $!-yr7
} J@/kIrx
} E'f{i:O"~
y B81f
0.Q Ujw
public void splitterStop() ] 7[ 3>IN
{ [CTnXb
bStop = true; M:=J^0
} H-!,yte
cRC6 s8
(fhb0i-
} "syI#U{
kl"hBK#D%
_kC-dEGf!y
/* 1;* cq
**FileAccess.java %6t:(z
*//文件访问(定位，写) xEa\f[.An
package NetFox; b3P+H r
import java.io.*; 8%:Iv(UMk
^23~ZHu
d.aS{;pse
public class FileAccessI implements Serializable{ 0RzEY!9g+
XjBW9a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gZVc 5u<
RandomAccessFile oSavedFile; 9FF0%*tGo
long nPos; 1l9G[o *
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(xycJ`N
public FileAccessI() throws IOException ??5Q)Erm1
{ ]iVcog"T
this("",0); >k|5Okq g
} _9ao?:
rDtY[
C-xr"]#]
public FileAccessI(String sName,long nPos) throws IOException D#aDv0b
{ n>z9K')
oSavedFile = new RandomAccessFile(sName,"rw"); sVQ|*0(J0r
this.nPos = nPos; 4>YR{
oSavedFile.seek(nPos); _r#Z}HK
} $L`d&$Vh
VD AaYDi
I]|Pq
public synchronized int write(byte[] b,int nStart,int nLen) e v}S+!|U
{ SZ7:u895E
int n = -1; q$L%36u~/
try{ l03B=$
oSavedFile.write(b,nStart,nLen); j{ ]I]\=?
n = nLen; LG0;#3YwH
} q~Hn-5H4Q
catch(IOException e) MBK^FR-K
{ 2g `o
e.printStackTrace (); Ha#=(9.
} pp?D7S
_`$qBw.Nx
eSn+B;
return n; XTs8s12
} j8i[ONq^
>tS'Q`R
@/~omg}R
} (y'hyJo
9yu\ Ot
ho{*Cjv
/* BU)U/A8iS
**SiteInfoBean.java W-f=]eWg
*/ <\y@*fg+
package NetFox; O^PKn_OJ
a~`eQ_ND
;<Sd~M4f
public class SiteInfoBean { 2>9C-VL2
)iX~}7
L<S9
private String sSiteURL; //Site's URL qx(xvU9
private String sFilePath; //Saved File's Path ~\SGb_2
private String sFileName; //Saved File's Name yF:1( 4
private int nSplitter; //Count of Splited Downloading File ;a!S!%.h
T"Y+m-<%
234p9A@
public SiteInfoBean() @u+]aI!`-
{//nSplitter的缺省值为5 68|E9^`l
//default value of nSplitter is 5 urc| D0n
this("","","",5); Kg*Q
} "!P3R1;%
KkyVSoD\
5ta `%R_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &E F!OBR
{ ,,.QfUj/&
sSiteURL= sURL; g/_5unI}u
sFilePath = sPath; ^e5=hH-%
sFileName = sName; _ye |Y
this.nSplitter = nSpiltter; MKCsv+
TqQB@-!
"cGk)s
} ztY}5A2`
Paq4
$Wol?)z
public String getSSiteURL() h*a(_11
{ A2FYBM`Q&D
return sSiteURL; ?81c 4w
} AN m d!
aK~8B_5k8
[aLI '
public void setSSiteURL(String value) ;1=1:S8
{ 2.y-48Nz
sSiteURL = value; T{^rt3a
} rXq.DvQ
A@('pA85
T<>,lQs(a
public String getSFilePath() (E3b\lST
{ B mb0cFQ
return sFilePath; [DOckf oZx
} 8W7J3{d
)q4[zv9
>|=ts
public void setSFilePath(String value) Uc>lGo1j
{ MchA{p&Ol
sFilePath = value; LOYk9m
} (mB&m@-N
}>|s=uGW
Y|qTyE%
public String getSFileName() ,qwuLBW
{ yPp9\[+^j
return sFileName; ~8+ Zs
} {Xy5pfW Q
G_JA-@i%
q i;1L Kc
public void setSFileName(String value) tOD6&<
{ djZqc5t
sFileName = value; FV!q!D
} WU` rh^
Fo_sgv8O<
ajT*/L!0_
public int getNSplitter() kD%( _K5
{ 'LC1(V!_j
return nSplitter; T-L||yE,h
} \)[j_^
j$:~Rek
}X6m:#6
public void setNSplitter(int nCount) *^4"5X@
{ mJnIwdW*
nSplitter = nCount; J8(lIk:e
} ]m<$}
} CRE3icXbQ
RqrdAkg
tk`v:t!6U
/* X_h}J=33Q
**Utility.java ~mxO7cy5Cg
*/ Fxz"DZY6
package NetFox; =T@1@w
~!L}yw
7$=InK
public class Utility { kJ}`V
Hn"RH1Zy
GVn!O1jio
public Utility() n>YKa)|W`
{ VONDc1%ga
0h_|t-9j
Yq KCeg
} D,feF9
=,M5KDk`
//线程睡眠 :I#V.
public static void sleep(int nSecond) .q>iXE_c
{ &8lZNv8;(p
try{ ux4POO3C|
Thread.sleep(nSecond); #6=
} (<9u-HF#
catch(Exception e) "to;\9lP
{ 4r}51 N\
e.printStackTrace (); hgq;`_;1,
} 4WB0Pt{
} M= (u]%\
})%{AfDRF
//日志 |6-nbj
public static void log(String sMsg) AK4t\D)K1
{ !a\^Sk /
System.err.println(sMsg); 59u}W 0
} >(<f 0
L4W5EO$
h*\%vr
public static void log(int sMsg) :2`e(+Uz
{ He@KV=
System.err.println(sMsg); %|oym.-I6
} m&3xJuKih
} :3 mh@[V
$`8wJf9@w
z1a7*)8P
/* KI.hy2?e
**TestMethod.java d'> x(Yi
*/ c+ie8Q!
package NetFox; [}m[)L\
?Bmb' 3
:`sUt1Fw.
public class TestMethod { kJR`:J3DJ
|.dRily+
Z\sDUJ
public TestMethod() i6Gu@( 8Q
{ ///xx/weblogic60b2_win.exe z$sGv19pB
try{ zQ PQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8P`"M#fI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :4|4=mkr
SiteFileFetch fileFetch = new SiteFileFetch(bean); j>kqz>3
fileFetch.start(); RnN!2K
} %TqC/c
catch(Exception e){e.printStackTrace ();} &^nGtW%a 9
U0+-W07>
O6Y0XL
} rC5O")I<
An@t?#4gxi
xSu >
public static void main(String[] args) 6LhTBV
{ 5r0YA IJ
new TestMethod(); Ys7]B9/1O
} 7EJ+c${e.-
} *1"+%Z^
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