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)); q% *-4GP
} .LMOmc=(
for(int i=0;i<nEndPos.length-1;i++) IsP-[0it
{ e1ts/@V
nEndPos = nStartPos[i+1]; =A[:]),v
} =Y!x
nEndPos[nEndPos.length-1] = nFileLength; YD>5zV%!D
} jT/}5\
} +c'b=n9j
g2)jd[GM
gJ;jh7e@
//启动子线程 k%2woHSu&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^K[WFiN}
for(int i=0;i<nStartPos.length;i++) !A_<(M<
{ }#'I,?_k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [&H$Su}$0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b~$B0o)
nStartPos,nEndPos,i); DNTkv_S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3%HF"$Gg
fileSplitterFetch.start(); 9rD6."G
} PH!^ww6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f[r?J/;P9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'OEh'\d+x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `eZ +Pf".
nEndPos = " + nFileLength); R;yi58Be
// fileSplitterFetch[nPos.length-1].start(); lSW6\jX
5l_ >QB
V%|CCrR
//等待子线程结束 *aem5E`c
//int count = 0; ?so=k&I-M
//是否结束while循环 J]h$4"
boolean breakWhile = false; c qWX*&2_
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<xn96|$
while(!bStop) \}:RG^*m
{ &Hl*Eg f
write_nPos(); H]I^?+)9
Utility.sleep(500); O4c[,Uq8~
breakWhile = true; !\'NBq,
h eR$j
@Yzdq\FI
for(int i=0;i<nStartPos.length;i++) _0GM!Cny
{ mKTa.
if(!fileSplitterFetch.bDownOver) EdC^L`::
{ [<0\v<{`L
breakWhile = false; b '9L}q2m
break; @gc|Z]CV
} 'c[|\M!u
} {.HFB:<!}
if(breakWhile) v,eTDgw
break; __mnz``/Y
e6 &-f
178u4$# b
//count++; eV"Za.a.
//if(count>4) 0m&
// siteStop(); $ap6Vxjr
} Bu{1^g:
{J[5 {]Je[
Y%GIKtP
System.err.println("文件下载结束！"); ?7eD<|
} <T^:`p/]4
catch(Exception e){e.printStackTrace ();} ' K\ $B_
} .a@>1XO
<+r<3ZBA
n[f<]4<
//获得文件长度 12olVTuw
public long getFileSize() kv8 /UW
{ GEd JB=
int nFileLength = -1; {=Y3[
try{ jmkVolz
URL url = new URL(siteInfoBean.getSSiteURL()); KD(}-zUs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cju%CE3a
httpConnection.setRequestProperty("User-Agent","NetFox"); #q-7#pp
USrBi[_ci\
=X24C'!Mpe
int responseCode=httpConnection.getResponseCode(); 13f@Ox$
if(responseCode>=400) S!JwF&EW
{ jb'AOs
processErrorCode(responseCode); } N$soaUs
return -2; //-2 represent access is error $Y3mO~
} %=G*{mK
i,R+C.6{
"'9[c"Iz
String sHeader; wU $j/~L
QKAt%"1&
+#wh`9[wBt
for(int i=1;;i++) Up*.z\|'y
{ gQ8FjL6?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @TqqF:c7
//Utility.log(in.readLine()); {wS)M
sHeader=httpConnection.getHeaderFieldKey(i); MEled:i
if(sHeader!=null) R>CIEL
{ \[CPI`yQe
if(sHeader.equals("Content-Length")) q2U8]V U)
{ Kc,=J?Ob
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KhFw%Z0s<
break; wusj;v4C4M
} KJQW))%e
} iQ7S*s+l5O
else K4`)srd
break; ,+mH1#-3
} {OBV+}#
} 9irT}e
catch(IOException e){e.printStackTrace ();} -w3KBlo
catch(Exception e){e.printStackTrace ();} \])-Bp,
or)v:4PXW
f*HEw
Utility.log(nFileLength); piPx8jT`F
u}~jNV
7{fOo%(7
return nFileLength; ]A%S&q
} -rXo}I,VI
"$6 .L^9W
W}0cM9 g
//保存下载信息（文件指针位置） `rQDX<?
private void write_nPos() 7JL*y\'
{ 5+yT{,(5
try{ 8-.jf
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6%Ws>H4@|
output.writeInt(nStartPos.length); :3h'Hr
for(int i=0;i<nStartPos.length;i++) E|`JmfLQu
{ fx#Krr@
// output.writeLong(nPos); x } X1 O)
output.writeLong(fileSplitterFetch.nStartPos); )/4xR]
output.writeLong(fileSplitterFetch.nEndPos); 7~H.\4HB
} T:?01?m
output.close(); 8-clL\bm
} sQ05wAv
catch(IOException e){e.printStackTrace ();} _W +
catch(Exception e){e.printStackTrace ();} ?K>=>bS^h
} FsTl@zN
>^|(AzS
Dc;zgLLL
//读取保存的下载信息（文件指针位置） wB0Ke
private void read_nPos() *v6 j7<H
{ K2gg"#ft?
try{ 0n('F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HgfeSH
int nCount = input.readInt(); PD$@.pib
nStartPos = new long[nCount]; `k.Nphx~%
nEndPos = new long[nCount]; PEIf)**0N
for(int i=0;i<nStartPos.length;i++) _G1C5nkDl4
{ DwBKqhu
nStartPos = input.readLong(); s;NPY
nEndPos = input.readLong(); x=jS=3$8
} @Z{!T)#}j
input.close(); ?VaAVxd29
} tLc9-
catch(IOException e){e.printStackTrace ();} DuzJQSv
catch(Exception e){e.printStackTrace ();} #OE]'k Ss
} p^/6Rb"e
Z<M?_<3
Zwm2T3@e
private void processErrorCode(int nErrorCode) B!iz=+RNC1
{ !W?6,i-]
System.err.println("Error Code : " + nErrorCode); U)B^R
} Dqh rg;
5$;#=WAY
Gj9WUv[P
//停止文件下载 l:?w{'i$
public void siteStop() |bWvQdN
{ ;wF 0s
bStop = true; -Uu65m~:{k
for(int i=0;i<nStartPos.length;i++) 8e{S(FZ7Ed
fileSplitterFetch.splitterStop(); yWkg4
p%?m|(4f
c^a Dr
} ']cRSj.
} i<ug("/
//负责部分文件的抓取 ,rZp(moj
**FileSplitterFetch.java hNWZ1r~_
*/ \cKY{(E
package NetFox; ;kv/(veQ1<
f:_mrzz
[Kc"L+H\
import java.io.*; $T%~t@Cv1
import java.net.*; b!hs|emo;
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/6@~XO)w
public class FileSplitterFetch extends Thread { M,V~oc5
: #om6}
B>=NE.ulUL
String sURL; //File URL XNd%3rm,
long nStartPos; //File Snippet Start Position KDQqN]rg
long nEndPos; //File Snippet End Position 08 $y1;
int nThreadID; //Thread's ID -<MA\iSP
boolean bDownOver = false; //Downing is over $22_>OsA
boolean bStop = false; //Stop identical @_ Q
FileAccessI fileAccessI = null; //File Access interface C 7e
YrRD3P.P
`$hna{e^n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5&QDZnsl
{ +q NX/F
this.sURL = sURL; t!S ja
this.nStartPos = nStart; ML9nfB^z!
this.nEndPos = nEnd; E` O@UW@
nThreadID = id; w4UaWT1J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H,Ik&{@j
} I]dt1iXu_{
Nd] w I|>
FK~FC:K
public void run() OwJZ?j&)
{ <.6bni )
while(nStartPos < nEndPos && !bStop) gs?=yNL
{ ^qgOgu
)08mG_&atL
pD)$O}
try{ U!xOJ
URL url = new URL(sURL); ImnN&[Cu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4PsJs<u
httpConnection.setRequestProperty("User-Agent","NetFox"); s1/:Ts[3i
String sProperty = "bytes="+nStartPos+"-"; ?oKY"C8/
httpConnection.setRequestProperty("RANGE",sProperty); |}YeQl
Utility.log(sProperty); Q \E[py
&Fxw19[G
'i5V6yB
InputStream input = httpConnection.getInputStream(); c/bIt
//logResponseHead(httpConnection); `tZ-8f
XNm%O
O F|3y~z
byte[] b = new byte[1024]; K$K6,54y
int nRead; <m7T`5+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R,'` A.Kk
{ 2:>|zmh_
nStartPos += fileAccessI.write(b,0,nRead); Q,1TD2)h
//if(nThreadID == 1) FSp57W$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4Em$L]7
} @}Y,A~
B > sTM
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Utility.log("Thread " + nThreadID + " is over!"); $u`v k|\R
bDownOver = true; :vqfWK6mv
//nPos = fileAccessI.write (b,0,nRead); YH%aPsi
} HS% P
catch(Exception e){e.printStackTrace ();} @fML.AT
} n%"0%A
} w N-np3k
k~<b~VcU
/<\B8^yQ
//打印回应的头信息 { 4(E @
public void logResponseHead(HttpURLConnection con) Gxj3/&]^Y
{ ?uq7K"B
for(int i=1;;i++) ?[|T"bE5[
{ 6tKm'`^z4
String header=con.getHeaderFieldKey(i); j|N8"8"
if(header!=null) I`O)I&KH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tmCm54
Utility.log(header+" : "+con.getHeaderField(header)); e!:/enQo
else m)]A$*`<
break; D)u 9Y
} lQnl6j
} b.<>CG'
DKcg
pX nY=
public void splitterStop() K1F,M9 0]
{ 2`-yzm
bStop = true; vw'`t6
} gx*rxid
7:Jyu/*]
J:{$\m'
} TvEN0RV2
P[.BK
q $Hg\ {c
/* _-vf<QO]
**FileAccess.java fCA/
*//文件访问(定位，写) ~}c`r4
package NetFox; E>BP b
import java.io.*; | Q Y_ci
k#4%d1O}
ON(H7
public class FileAccessI implements Serializable{ 6Q&*V7EO
j:yQP#U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "iCR68e
RandomAccessFile oSavedFile; &*I\~;1
long nPos; 09f:%!^u
<eObQ[mQ
yMQuM:d
public FileAccessI() throws IOException :y?xS
{ 6~ *w~U
this("",0); q/o|uAq
} 5aF03+ko
Yfk){1
CvCk#:@HM
public FileAccessI(String sName,long nPos) throws IOException b6IYo!3
{ RP2MtP"M
oSavedFile = new RandomAccessFile(sName,"rw"); "d a%@Zy
this.nPos = nPos; [e2sUO0~r
oSavedFile.seek(nPos); iY=M67V
} -%&_LE9ZtS
'L*nC T;
|g5B==KI
public synchronized int write(byte[] b,int nStart,int nLen) |(gq:O
{ U/ncD F%C
int n = -1; c2}?[\U]
try{ x?J- {6k
oSavedFile.write(b,nStart,nLen); `?Pk~7
n = nLen; 73$^y)AvY
} ZQT14.$L
catch(IOException e) Gy9+-7"V
{ la ~T)U7
e.printStackTrace (); |kvom 4T
} Y[AL!h
wVvk{tS
Zho d%n3
return n; SRl:+!@.
} <RmI)g>'_^
K2T&U$,
Epm\=s
} #zC_;u$
.:tAZZ
\(t.|
/* AL/q6PWi
**SiteInfoBean.java .6%-Il
*/ [&n2 yt
package NetFox; @ 8yV15!
;z;O}<8s
hKw4[wB]
public class SiteInfoBean { \ajy%$;$}
^Bw2y&nN
Cf`s:A5<J
private String sSiteURL; //Site's URL =6b^j]1
private String sFilePath; //Saved File's Path 8kQ >M
private String sFileName; //Saved File's Name <d,Qi.G4
private int nSplitter; //Count of Splited Downloading File Z~^)B8
1 dT1DcZ
.P\wE";
public SiteInfoBean() l~,5)*T
{//nSplitter的缺省值为5 YC#N],#
//default value of nSplitter is 5 <6`_Xr7)
this("","","",5); w-?_U7'
} n7`R+4/s
Bk&ry)`gD
q/,>UtRr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NF <|3|
{ v*'dA^Q
sSiteURL= sURL; Al="ss&2
sFilePath = sPath; 7A|n*'[T>
sFileName = sName; z{U2K'
this.nSplitter = nSpiltter; dieGLA<5_X
=Jfo=`da
N;ed_!
} !Mp.jE
H%`Ja('"p
62~8>71;'
public String getSSiteURL() F$P8"q+
{ Y.&nxT95=
return sSiteURL; &U%AVD[
} Su99A.w
-ju&"L B
!, Y1FC
public void setSSiteURL(String value) /1ZRjf^
{ x5_V5A/@LU
sSiteURL = value; .}Va~[0j
} lB9 9J"A
R7u&`
+jQHf-l
public String getSFilePath() }t}y
{ {\3ZmF
return sFilePath; ^6R?UG;6
} x"q!=&>f
F}p)Q$0
`6a
public void setSFilePath(String value) <7-:flQz~
{ c:(Xkzj
sFilePath = value; g{wOq{7V
} Q-<N)K$F(4
J{fTx@?(
SPfz/ q{
public String getSFileName() ,@1rP55
{ ,MH/lQq%
return sFileName; ~JhH ,E
} [\eh$r\
~n9x ,
'/l<\b/E
public void setSFileName(String value) _Q)rI%A2
{ MYyV{W*T>
sFileName = value; 1.29%O8V_
} o~<ith$A*
/>^sGB
}7)iLfi
public int getNSplitter() w)}' {]P"c
{ L\;n[,.
return nSplitter; ;ED` 7
} _{$eOwB
{vCB$@/o
'x/pV5[hQ
public void setNSplitter(int nCount) .8[*`%K>
{ zsM3 [2E*
nSplitter = nCount; n{'LF #4l
} T$w`=7
} FYe#x]ue
i`k{}!F
E}-Y!,v^
/* ,%Go.3i[
**Utility.java ZQ@Ul
*/ o'Rr2,lVi
package NetFox; y}5:CZ
/[V}
wlC7;u
public class Utility { u7>{#]
fX:=_c
T~D2rt\
public Utility() /+ yIcE(&3
{ ,M?K3lG\g[
|[+/ ]Y
X}fu $2
} J?y0RX
/TEE<\"
//线程睡眠 zEBUR%9
public static void sleep(int nSecond) g.,_E4L
{ 5Z]]xR[
try{ Ns2<wl-
Thread.sleep(nSecond); B!j7vXM2
} yiO/0nMp
catch(Exception e) EX"o9'
{ 59k[A~)~
e.printStackTrace (); OyG#
} |~]@hs~
} r,8~qHbOT
lnQfpa8j
//日志 +{b3A@f|F
public static void log(String sMsg) :iEIo7B
{ d_] sV4[
System.err.println(sMsg); OAiSE`
} bmP2nD6
k1_"}B5
e8,!x9%J
public static void log(int sMsg) nhImO@Q:
{ JqTR4[`Z\
System.err.println(sMsg); B;Dl2k^L
} :k/Z|
} hanS8
{b,#l]v
n4A#T#D!t3
/* o,yZ1"
**TestMethod.java wf""=;
*/ Nc_Qd4<[@G
package NetFox; X%R)
"lnI@t{o
$ISx0l~
public class TestMethod { ~{00moN"m
I&Z+FL&@f
@.8FVF
public TestMethod() XGcl9FaO}
{ ///xx/weblogic60b2_win.exe 'z$!9ufY,
try{ P ~rTuj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q&`if O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p%#=OtkC
SiteFileFetch fileFetch = new SiteFileFetch(bean); rp_Aw
fileFetch.start(); VlFhfOR6t
} OhiY <
catch(Exception e){e.printStackTrace ();} qBF}-N_
)u>/:
"NvB@>S
} fqm-?vy}
zW:r7 P.
:Oh*Q(>
public static void main(String[] args) e3=-7FU
{ <d~IdK'\x
new TestMethod(); VpyqVbx1
} /;;$9O9
} Z"N}f ,
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