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)); %<(d%&~
} |l+5E
for(int i=0;i<nEndPos.length-1;i++) 8B?U\cfa^
{ ~~-VScG&
nEndPos = nStartPos[i+1]; ftR& 5!Wm
} =&$z Nc4h
nEndPos[nEndPos.length-1] = nFileLength; c3g`k"3*`
} ?Y,^Moc:
} 'xxM0Kn`
7H< IO`
*URT-+'
//启动子线程 tzIP4CR~F&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 111A e*U
for(int i=0;i<nStartPos.length;i++) 5:f!EMb
{ L6{gwoZf3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F=1 #qo<?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a{hc{
nStartPos,nEndPos,i); EGQgrwY5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _avf%OS
fileSplitterFetch.start(); |.0~'
} %\T,=9tD\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K3[+L`pz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~h;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U{M3QOF
nEndPos = " + nFileLength); @=dv[P"jn
// fileSplitterFetch[nPos.length-1].start(); x0(bM g>7
6Jb0MX"AVr
A?!RF7v
//等待子线程结束 6{1=3.CL
//int count = 0; ,S=[#
//是否结束while循环 rD SYR\cg
boolean breakWhile = false; 0r1GGEW`s
9 $$uk'}w!
\+O.vRc"M
while(!bStop) FrXP"U}Y
{ Nn FR;
write_nPos(); cVL|kYVWT
Utility.sleep(500); |zpy!X3
breakWhile = true; W wPzm?30
K8X7IE
Hf]:mhH
for(int i=0;i<nStartPos.length;i++) 9AX}V6\+
{ u5k{.&
if(!fileSplitterFetch.bDownOver) L4m Vk
{ `HXv_9
breakWhile = false; zH}3J}
break; 5buW\_G)
} D~ Y6%9
} n*wQgC'vw
if(breakWhile) i`r`Fj}-S-
break; BL16?&RK
Nb&j?./
3U{ mC}F
//count++; >U{iof<
//if(count>4) /)Cfm1$ic
// siteStop(); iv *$!\Cd
} %0C [v7\
.F 6US<]
}]o8}$&(
System.err.println("文件下载结束！"); Nbd4>M<
} y&,|+h
catch(Exception e){e.printStackTrace ();} -|#{V.G3'
} Bc"MOSV0
Yjc U2S"=P
7b>_vtrt
//获得文件长度 WK`o3ayH-
public long getFileSize() ;kk[x8$
{ & mOn]
int nFileLength = -1; rAu%bF
try{ -!1=S: S
URL url = new URL(siteInfoBean.getSSiteURL()); uNyN[U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5cIZ_#
httpConnection.setRequestProperty("User-Agent","NetFox"); EyA ny\"
<}{<FXk[
)-)rL@s.
int responseCode=httpConnection.getResponseCode(); MOaI~xZ
if(responseCode>=400) iF^qbh%%E
{ ^:{8z;w!(
processErrorCode(responseCode); yogavCD9b/
return -2; //-2 represent access is error \(i'iC
} l[$GOLeS
cj>UxU][eS
72OqXa*
String sHeader; rwLKY.J]
v}j5G, [-
Qy"Jt]O
for(int i=1;;i++) &S{r;N5u
{ ,XEIg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *gwlW/%Fz
//Utility.log(in.readLine()); MrHJ)x"hy
sHeader=httpConnection.getHeaderFieldKey(i); %@Gy<t,
if(sHeader!=null) DlUKhbo$g
{ Q`9c/vPU
if(sHeader.equals("Content-Length")) UXBWCo;-
{ 1,+<|c)T?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gD6S%O
break; aKriO
} }g/u.@E
} 4)w,gp
else Z|n|gxe
break; {O2=K#J
} =;0-t\w!
} q!:dZES
catch(IOException e){e.printStackTrace ();} [n[dr@J7v
catch(Exception e){e.printStackTrace ();} R BHDfm'~7
(Ut8pa+yX
n>,:*5"G
Utility.log(nFileLength); 'M~`IN`
*ai~!TR
$\NqD:fgb
return nFileLength; e' l9
} ruGJZAhIA^
yk8b>.Y\A
Ljm`KE\Q;t
//保存下载信息（文件指针位置） `#ruZM066
private void write_nPos() D;> 7y}\
{ 'z8FU~oU
try{ t,fec>.
output = new DataOutputStream(new FileOutputStream(tmpFile)); uM`i!7}
output.writeInt(nStartPos.length); jlj ge=#c2
for(int i=0;i<nStartPos.length;i++) 66pjWS {X
{ Pjs=n7
// output.writeLong(nPos); (SRY(q
output.writeLong(fileSplitterFetch.nStartPos); ~6i'V?>
output.writeLong(fileSplitterFetch.nEndPos); g9" wX?*
} F9o7=5WAb
output.close(); / rc[HbNg.
} }dzdx"
catch(IOException e){e.printStackTrace ();} @.-S(MNR
catch(Exception e){e.printStackTrace ();} * |,N/e
} ^yPZ$Q
!{^kH;*u
IADHe\.
//读取保存的下载信息（文件指针位置） 3Tu]-.
private void read_nPos() T<0r,
{ HQP.7.w7 5
try{ Li6|c*K'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =\.*CY|;N
int nCount = input.readInt(); xZ`z+)
nStartPos = new long[nCount]; (-WRZLOQ
nEndPos = new long[nCount]; t\ oud{Cv
for(int i=0;i<nStartPos.length;i++) I%J>~=]n_
{ z+yq%O
nStartPos = input.readLong(); kZG.Id
nEndPos = input.readLong(); d MR?pbD
} v`,!wS
input.close(); OlCqv-B2&
} "HJ^>%ia
catch(IOException e){e.printStackTrace ();} ?{ExBZNa
catch(Exception e){e.printStackTrace ();} CO`)XB6W
} )7*'r@
cK1^jH<|
$~6MR_Yq
private void processErrorCode(int nErrorCode) 6HK1?
{ )=Z;H"_
System.err.println("Error Code : " + nErrorCode); s0' haU
} 32 i6j
~Tt@v`}
7_2D4CI
//停止文件下载 sg7h&<Xx
public void siteStop() CnB[ImMs(A
{ h}@wPP{
bStop = true; P_5aHeiJ
for(int i=0;i<nStartPos.length;i++) 06]3+s{{
fileSplitterFetch.splitterStop(); V#w$|2
INr1bAe$
h]s6)tII
} ym{@w3"S
} AT1cN1:4?
//负责部分文件的抓取 mzK0$y#*o
**FileSplitterFetch.java 2%WeB/)9
*/ A8&@Vxdz
package NetFox; -E|"?
UH>~Y N
7_ix&oVI
import java.io.*; z)C}}NH*!@
import java.net.*; #4m5I="
VF2,(f-*
6#U~>r/
public class FileSplitterFetch extends Thread { ]!AS%D`
FXBmatBck
"v:k5a(
String sURL; //File URL (O J/u)W^
long nStartPos; //File Snippet Start Position O6Py
long nEndPos; //File Snippet End Position 5&s6(?,Eu
int nThreadID; //Thread's ID 9Do75S{(
boolean bDownOver = false; //Downing is over $^fF}y6N
boolean bStop = false; //Stop identical 1TQ?Fxj
FileAccessI fileAccessI = null; //File Access interface Xq$-&~
AF#:*<Ev
~Yd[&vpQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 29J|eBvxx
{ 5.5kH$;>
this.sURL = sURL; |/K|Vwa
this.nStartPos = nStart; l{7}3Am6
this.nEndPos = nEnd; hn2:@^=f
nThreadID = id; .F7?}8>Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w0g@ <( 3
} v>LK+|U
YxM\qy{Vr
V5lUh#@TN&
public void run() iO*5ClB
{ tM"vIz 05
while(nStartPos < nEndPos && !bStop) dQIF'==6
{ =7+%31
KuwhA-IL
;t+p2i
try{ *}C%z(
URL url = new URL(sURL); @2"3RmYLo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Yv*f:
httpConnection.setRequestProperty("User-Agent","NetFox"); D 1.59mHsD
String sProperty = "bytes="+nStartPos+"-"; Nmx\qJUR(
httpConnection.setRequestProperty("RANGE",sProperty); R_G2C@y*
Utility.log(sProperty); 1K3XNHF
/)TeG]Xg
b<y*:(:
InputStream input = httpConnection.getInputStream(); y?UJ<QAi
//logResponseHead(httpConnection); TI3xt-/
3q4Zwv0z20
6k0Awcr
byte[] b = new byte[1024]; nX:E(9q7c
int nRead; "}_J"%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ="]r{
{ .<QKQ%-
nStartPos += fileAccessI.write(b,0,nRead); sd\}M{U
//if(nThreadID == 1) =iW hK~S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RCTqV.L
} CfW#Wk:8J
_XZK2Q[
q}Po)IUT`5
Utility.log("Thread " + nThreadID + " is over!"); =*'yGB[x)
bDownOver = true; ;cf$u}+
//nPos = fileAccessI.write (b,0,nRead); (KC08
} g"n>v c7
catch(Exception e){e.printStackTrace ();} TFb7P/g
} ]7<$1ta
} B)7:*Kj
8WDL.IO
e*'bY;8lo
//打印回应的头信息 b&!}SZ
public void logResponseHead(HttpURLConnection con) #8t=vb3
{ XwEMF5[
for(int i=1;;i++) hub]M
{ @XG1d)sE
String header=con.getHeaderFieldKey(i); eHUyV@
if(header!=null) {s@!N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ydsnu
Utility.log(header+" : "+con.getHeaderField(header)); Q#yHH]U)X
else mH;t)dT
break; N_:!uR
} Lfx a^0
} e6'0g=Y#
e;=R8i
l1zPL3"u_^
public void splitterStop() *H/)S5
{ sB:e:PK
bStop = true; XC6|<pru
} I;jH'._k#
br88b`L
:@&e~QP(
} 2A
~L&z?'V
|goBIp[
/* Ow?~+) 4
**FileAccess.java a?Fz&BE
*//文件访问(定位，写) 1y[~xxgE
package NetFox; R|Bi%q|4P
import java.io.*; t@lTA>;U@
Yw=@*CK'
nZj&Ma7R
public class FileAccessI implements Serializable{ c)Q-yPMl)
kxe{HxM$Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $Rze[3
RandomAccessFile oSavedFile; *RJD^hu
long nPos; A\mSS
>Heuf"V
M"c=_5P
public FileAccessI() throws IOException )LG!"~qiz
{ )5`^@zx
this("",0); |LIcq0Z
} KDg%sgRu}
/FXb,)1t
T^8`ji
public FileAccessI(String sName,long nPos) throws IOException 68~]_r.a
{ 0@'-g^PS
oSavedFile = new RandomAccessFile(sName,"rw"); hHMp=8J7
this.nPos = nPos; h{yh}04P1
oSavedFile.seek(nPos); *@lVesC2
} @?tR-L<u
(Z@-e^R
4%v-)HGh
public synchronized int write(byte[] b,int nStart,int nLen) P<1&kUZL
{ @pvQci
int n = -1; y1Br4K5C
try{ kazgI>"Q8
oSavedFile.write(b,nStart,nLen); }nM+"(}
n = nLen; q=cnY+p>
} hHEn
catch(IOException e) l;z+E_sQ
{ )@B!
e.printStackTrace (); W:f)#'
} Tpnwwx[]:|
|&S^L}V.C
h{]0 H'g
return n; qoQ,3&<
} wMm+E "}W
&_QD1 TT
sAX4giaLD
} ]*DIn1C^
&z\?A2Mw%
$\oe}`#o
/* &xj,.;
**SiteInfoBean.java 5 a&a-(
*/ Jk<b#SZ[b
package NetFox; v>hc\H1P
NCkrf]*F-
jRk1Iu|7
public class SiteInfoBean { ywjD.od"v
4}Os>M{k
v{SYz<(
private String sSiteURL; //Site's URL `sdbo](76
private String sFilePath; //Saved File's Path U z)G Y
private String sFileName; //Saved File's Name 0rDQJCm
private int nSplitter; //Count of Splited Downloading File <aMihT)dd
's8LrO(=
d8jP@>
public SiteInfoBean() '}Jq(ah(
{//nSplitter的缺省值为5 ;M#D*<ucI:
//default value of nSplitter is 5 noWwX
this("","","",5); gU@.IOg
} 8(6mH'^y
n?^X/R.22
vO;:~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "8[Vb#=*e
{ Ip,0C8T`Q
sSiteURL= sURL; SsL>K*t5
sFilePath = sPath; r)w]~)8
sFileName = sName; L~M6ca"
this.nSplitter = nSpiltter; Gnqun%
(j)>npOd9
P^/e!%UgC
} w\a9A#v,
@:u2{>Yl
5)K?:7
public String getSSiteURL() =-uk7uZM
{ 7:)$oH
return sSiteURL; {bp~_`O
} @rW%*?$7
1B`0.M'd
O;;vz+ j
public void setSSiteURL(String value) ^@q$c
{ V/DdV}n!
sSiteURL = value; `ucr;P
} `{@?O%UB
TSd;L u%hr
!B*d,_9c
public String getSFilePath() :B_ itl0{e
{ 'l'[U
return sFilePath; (Bfy
} 1'J|yq
w5&,AL:
"j+=py`
public void setSFilePath(String value) ~ @s$
{ ;Q8rAsf9
sFilePath = value; +(2mHS0_a
} 1j^FNg~
A|GheH!t
O7Awti-X
public String getSFileName() }qdGS<{
{ F;dUqXUu
return sFileName; )x&}{k6 %
} N|WR^MQD
Y]1b39O
)e:u 6]
public void setSFileName(String value) sJ/?R:
{ YR/rN,
sFileName = value; n&uD=-
} @k2nID^>
\c$!C8z
8|p*T&Cn&
public int getNSplitter() a?9Ka!O4s
{ >&N8Du*[
return nSplitter; M&O .7B1}
} t[cZ|+^]
1QH5<)Oa
{wp"zaa
public void setNSplitter(int nCount) owc#RW9 7
{ '=vD!6=0@
nSplitter = nCount; ng[ZM);
} R`|GBVbv
} [2cG 7A
sHulaX{
b]U%|bp
/* 9ozUg,+Z|J
**Utility.java p2~MJ LK4
*/ w;Na9tR
package NetFox; 2s@<k1EdPl
ZMXIKN9BF#
JB= L\E}
public class Utility { u=h/l!lR
W.u}Q@
$n?@zd@53
public Utility() ,;yiV<AD
{ OL|UOG
d^WEfH
<ibEo98
} L?e N(L
%<w)#eV?
//线程睡眠 ']ussFaQ
public static void sleep(int nSecond) `PR)7}/<
{ aJ1<X8
try{ r9uuVxBD
Thread.sleep(nSecond); !bG%@{WT
} />zE$)'M
catch(Exception e) a:tCdnK/
{ jn9KQe\3
e.printStackTrace (); iWZrZ5l
} kMz^37IFMG
} s`G3SE
r0)X]l7
//日志 ga~C?H,K
public static void log(String sMsg) "?GA}e"R
{ .* xaI+:
System.err.println(sMsg); ZVj/lOP X
} Ul@yXtj
+AyrKs?h
257pO9]
public static void log(int sMsg) fE;<)tU
{ wBUn*L
System.err.println(sMsg); 0;j)rmt
} ~P85Or
} s1xl*lKX%
V!F# ek:
<m#ov G6
/* "$*&bC#dE
**TestMethod.java B#_<?
*/ 2n]Br
package NetFox; dtw4cG
((}T^
tN=B9bm3j
public class TestMethod { Wi Mi0?$.
p#UrZKR
_>8ZL)NQQ
public TestMethod() ~e5hfZv|w
{ ///xx/weblogic60b2_win.exe ew#t4~hh
try{ WCc,RI0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %># VhK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %(IkUD
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9"3 7va
fileFetch.start(); K"O+`2$
} OsMU>v }m
catch(Exception e){e.printStackTrace ();} \s8j*
0?KY9
T\VKNEBo
} xG JX~)
p^~AbU'6~
F/FUKXxx
public static void main(String[] args) }]ak6'|[
{ o.ntzN
new TestMethod(); v&p|9C@
} HrH-e=j
} 5J^S-K^r
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