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)); fRwr}n'
} XaaR>HljJ
for(int i=0;i<nEndPos.length-1;i++) Rw<O%i5/d
{ .7+"KP:
nEndPos = nStartPos[i+1]; '(zP;
} 09=w
nEndPos[nEndPos.length-1] = nFileLength; _U o3_us
} l>6p')F!
} t^=S\1"R\
,uD}1 G<u
[[O4_)?el
//启动子线程 ;3iWV"&_A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q$5%9
for(int i=0;i<nStartPos.length;i++) 4WPco"xH!
{ ny0]Q@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P=a&>i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^[6#Kw&E
nStartPos,nEndPos,i); (ylZ[M&B:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iM$iZ;Tp
fileSplitterFetch.start(); +fHqGZ]
} 4YXp,U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mln%Rd6u/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S3Fj /2Q8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s~A:*2\
nEndPos = " + nFileLength); F5+!Gb En
// fileSplitterFetch[nPos.length-1].start(); +1K=]#a
!FQS9SoO9
O' Mma5
//等待子线程结束 @P">4xVX{
//int count = 0; _y:aPn
//是否结束while循环 \okvL2:!
boolean breakWhile = false; H|3CZ=U?
IH"_6s#$&
sfp.>bMj
while(!bStop) 9Qq%Fw_
{ pS8`OBenA
write_nPos(); ;,Os3
Utility.sleep(500); !>fi3#Fi
breakWhile = true; [7l5p(=
v?o("I[ C
aN';_tGvK
for(int i=0;i<nStartPos.length;i++) } :T}N]
{ <!-#]6
if(!fileSplitterFetch.bDownOver) !N/?b^y
{ 0IQ|`C.
breakWhile = false; KcM+8W\
break; ~7H?tp.Dw
} T^gi^{
} 4rypT-%^;
if(breakWhile) GXR7Ug}k
break; jF{)2|5
U8eU[|-8O/
LbnF8tj}h
//count++; fK{Z{)D
//if(count>4) b{,vZhP-
// siteStop(); j?(@x>HA
} ,UfB{BW
RPkOtRKL=w
-];Hb'M.!e
System.err.println("文件下载结束！"); h: zi8;(
} ze`qf%
catch(Exception e){e.printStackTrace ();} scZ'/(b-E
} Oe0dC9H
(Li)@Cn%
OQ _wsAA
//获得文件长度 3ZqtIQY`
public long getFileSize() <7oZV^nd *
{ 8u Z4[
int nFileLength = -1; nN(Q}bF
try{ ;zo?o t/
URL url = new URL(siteInfoBean.getSSiteURL()); ,-.=]r/s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [[Usrbf
httpConnection.setRequestProperty("User-Agent","NetFox"); 9!wm`'G8
?Q6ZZQ~
}9?fb[]
int responseCode=httpConnection.getResponseCode(); BgwZZ<B
if(responseCode>=400) pXe]hnY
{ tmC9p6%
processErrorCode(responseCode); &uJ7[m19z
return -2; //-2 represent access is error S4%MnT6Uy
} yF1^/y!@
WhL1OG
a;0$fRy
String sHeader; 9R|B 5.
@"`{Sh`Y$
hF-X8$[
for(int i=1;;i++) Y0nuwX*{
{ fQ,(,^!;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9'!I6;M
//Utility.log(in.readLine()); pl.=u0 *
sHeader=httpConnection.getHeaderFieldKey(i); <~Tfi*^+
if(sHeader!=null) 7@i2Mz/eV
{ MM Nz2DEy[
if(sHeader.equals("Content-Length")) JmVha!<qk
{ dUpOg{I.x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B'D4]EB
break; Alb5#tm:m
} WR>2t&;E
} zyFbu=d|O:
else eC-nV)]I9
break; s}":lXkrw
} mQt?d?6
} %suXp,j
catch(IOException e){e.printStackTrace ();} .g6(07TyV
catch(Exception e){e.printStackTrace ();} 2n5{H fpY
:6Sb3w5h
U_e e3KKA
Utility.log(nFileLength); p%*!]JRS
HUY1nb=
d:=:l?
return nFileLength; 2BIOA#@t
} veGRwir
]ipltR7k
V %Rz(a+c
//保存下载信息（文件指针位置） pi?U|&.1z
private void write_nPos() %GDs/9
{ Gnmxp%&}P|
try{ atWAhN
output = new DataOutputStream(new FileOutputStream(tmpFile)); XWFuAE
output.writeInt(nStartPos.length); ]#oqum@Yf1
for(int i=0;i<nStartPos.length;i++) t2vo;,^euL
{ Ic&Jhw;]z
// output.writeLong(nPos); [KjL`
output.writeLong(fileSplitterFetch.nStartPos); @g'SH:}
output.writeLong(fileSplitterFetch.nEndPos); GGchNt
} pxs`g&3yd
output.close(); j*;/Cah]k
} RJZ4fl
catch(IOException e){e.printStackTrace ();} %O3 r>o=
catch(Exception e){e.printStackTrace ();} 79Vp^GG7
} z|>f*Z
]Q\/si&
?{I]!gI
//读取保存的下载信息（文件指针位置） YNi3oG]h
private void read_nPos() H"> }yD
{ >|So`C3:e
try{ kzLtI w&.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h|Uy!?l
int nCount = input.readInt(); K-*q3oh G
nStartPos = new long[nCount]; u.sn"G-c
nEndPos = new long[nCount]; 6~v|pA jY
for(int i=0;i<nStartPos.length;i++) /h'b,iYVV
{ (Dx]!FFz
nStartPos = input.readLong(); y|@=j~}Zq
nEndPos = input.readLong(); U0W- X9>y
} *QpKeI
input.close(); gRdg3qvU
} 5zH?1Z~*
catch(IOException e){e.printStackTrace ();} O~AOZ^a:2
catch(Exception e){e.printStackTrace ();} xN#. Pm~
} B]YY[i
$?u ^hMU=
(S#4y
private void processErrorCode(int nErrorCode) ?(CMm%(8
{ 8"g.Z*
System.err.println("Error Code : " + nErrorCode); e RjpR?!\
} )v67wn*1A
H A(e
Lqv5"r7eV
//停止文件下载 Q!VPk~~(
public void siteStop() xl$#00|y
{ Y-WYQ{
bStop = true; Q[k7taoy
for(int i=0;i<nStartPos.length;i++) KwiTnP!Dca
fileSplitterFetch.splitterStop(); KD7RI3'?
cTeEND)
v+|N7
} nUvxO `2
} 8y{<M"v+/
//负责部分文件的抓取 ctL@&~*nY
**FileSplitterFetch.java lS(?x|dO
*/ 43Yav+G(+
package NetFox; 'L2M W
oA&V,r
6Hn3
import java.io.*; }GCt)i_
import java.net.*; Oj*3'?<7=
&` u<KKF6
0iX;%SPYz
public class FileSplitterFetch extends Thread { \Podyh/;?
p|M 8ww
b!ZXQn3X<
String sURL; //File URL ODH@/
long nStartPos; //File Snippet Start Position }I'g@Pw9[
long nEndPos; //File Snippet End Position (SLAq$gvd
int nThreadID; //Thread's ID 1v4(
boolean bDownOver = false; //Downing is over e/m,PE
boolean bStop = false; //Stop identical Z?5kO-[
FileAccessI fileAccessI = null; //File Access interface \S@;>A<J
'%`Wy@
{qCmZn5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WKQVT I&A.
{ 8eSIY17
this.sURL = sURL; *Ki ],>_~
this.nStartPos = nStart; u9FXZK7
this.nEndPos = nEnd; +]Y&las
nThreadID = id; +t R6[%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $3sS&i<
} !0~$u3[b
+?~'K&@
u4=j!Zb8}
public void run() e1X*}OI
{ pCNihZ~
while(nStartPos < nEndPos && !bStop) M ,8r{[2
{ D!~-53f@
++:vO
B8_w3;x
try{ 5[M?O4mi
URL url = new URL(sURL); Cd#>,,\z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1@kPl[`p'
httpConnection.setRequestProperty("User-Agent","NetFox"); jl=<Q.Mm7
String sProperty = "bytes="+nStartPos+"-"; !c\d(u
httpConnection.setRequestProperty("RANGE",sProperty); )>Oip
Utility.log(sProperty); o)7gKWjujP
-tSWYp{
tH<v1LEZN
InputStream input = httpConnection.getInputStream(); ZgLO[Bj
//logResponseHead(httpConnection); E{d Mdz
tqIz$84G
s&p*.I]@>
byte[] b = new byte[1024]; *tjE#TW
int nRead; 2i4FIS|z0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @M?N[LG
{ A:1O:LB=!
nStartPos += fileAccessI.write(b,0,nRead); t#~r'5va
//if(nThreadID == 1) nv(Pwb3B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N G1]!Vz5
} |$":7)eH!
AU}P`fT!
&eT)c<yhyK
Utility.log("Thread " + nThreadID + " is over!"); 'N],d&fu^^
bDownOver = true; Uq&ne1
//nPos = fileAccessI.write (b,0,nRead); bh?Vufd%)
} uYS?# g
catch(Exception e){e.printStackTrace ();} =8j;!7p
} pc5-'; n
} SHPaSq'&N
Rs:<'A
G.O0*E2V
//打印回应的头信息 #H(|+WEu
public void logResponseHead(HttpURLConnection con) )]!Ps` ,u
{ rB}UFS)
for(int i=1;;i++) [syuoJ
{ 0b=OK0n!%
String header=con.getHeaderFieldKey(i); 3Qe:d_
if(header!=null) _Q/D%7[pa
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j_\sdH*r
Utility.log(header+" : "+con.getHeaderField(header)); kqSCKY1
else {!xPq%
break; |,5b[Y"Dt
} 0X-u'=Bs
} er^z:1'
fSl+;|Kn
-[v:1\Vv
public void splitterStop() O1coay
{ "=H7p3
bStop = true; ;'dw`)~jQ
} X(1nAeQ
GdR>S('
9'Y~! vY
} {J%hTjCw
/Yc!m$uCW
yEtSyb~GK
/* U}6'_ PRQ
**FileAccess.java /9|1eSUa
*//文件访问(定位，写) |v}"UW(y
package NetFox; tz&=v,_jc
import java.io.*; \^?BC;s^C
*4r 1g+0
._=Pa)T
public class FileAccessI implements Serializable{ 6 EE7<&
[Zl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RP7e)?5$s
RandomAccessFile oSavedFile; /+P 4cHv]F
long nPos; ${KDGJ,^
*(s+u~, I
?.IT!M}DR
public FileAccessI() throws IOException WO)rJr!C
{ 6t TLyI$+
this("",0); r`i<XGPJ%
} -Duy:C6W
+%6{>C+bZo
S3:Pjz}t
public FileAccessI(String sName,long nPos) throws IOException J+[&:]=P
{ -fz |
oSavedFile = new RandomAccessFile(sName,"rw"); .jZmQtc
this.nPos = nPos; >;nE.]
oSavedFile.seek(nPos); A"\kdxC
} mmAikT#k
#wNksh/J^
HW"|Hm$Y(
public synchronized int write(byte[] b,int nStart,int nLen) z*YkD"]B
{ %z J)mOu
int n = -1; AR]y p{NS
try{ II)\rVP5
oSavedFile.write(b,nStart,nLen); PLKp<kg
n = nLen; IBf&'/ 8\
} rv&(yA
catch(IOException e) S$+vRX7
{ ,4jkTQ*@2
e.printStackTrace (); wZh&w<l'
} @xmO\
['sj'3cW-
qWHH% L;
return n; Va\dMv-b
} qWGnIPk
n(/(F`
R(kr@hM
} 5 1@V""m
|J'@-*5?[8
0V"r$7(}
/* Cv>|>Ob#
**SiteInfoBean.java )(9>r/bq
*/ ?&_ -,\t
package NetFox; CK 3]]{
EJ.oq*W!*J
VD;Ot<%
public class SiteInfoBean { V2,54YE
U voX\
GX&BUP\
private String sSiteURL; //Site's URL =_\5h=`Yx
private String sFilePath; //Saved File's Path n%"q>
private String sFileName; //Saved File's Name 7!#x-KR~5
private int nSplitter; //Count of Splited Downloading File "nU5c4
efy65+~GG
>zFe)
public SiteInfoBean() `g<@F^x5
{//nSplitter的缺省值为5 6,G1:BV{K
//default value of nSplitter is 5 BdG~y1%:
this("","","",5); "2i{ L '
} ZvpcjP
.|JJyjRA+
v98=#k!F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mhm3u
{ }\:3}'S.$
sSiteURL= sURL; hq6fDRO/4
sFilePath = sPath; 1Zx|SBF
sFileName = sName; HlqCL1\<
this.nSplitter = nSpiltter; 4!i`9w$$"
u01 'f-h
sD7Qt
} ;3U-ghj
#M$[C d I$
Jor>YB`X
public String getSSiteURL() -ZlBg~E
{ zIi|z}WJ
return sSiteURL; TUIj-HSe
} &W-L`aFd0
wOOBW0tj
dQYb)4ir
public void setSSiteURL(String value) ^ ~:f02[D
{ wdS^`nz|
sSiteURL = value; );_g2=:#
} ]@Y8! ,
b4Br!PL@G
h$)(-_c3
public String getSFilePath() ah1d0eP
{ G+stt(k:
return sFilePath; mp!KPw08':
} <{bQl L
)XmV3.rI
klxVsx%I{G
public void setSFilePath(String value) f_}/JF
{ nT..+J)
sFilePath = value; 9W:oo:dK F
} P9p:x6
SUINV_>7
_G|hKk^,
public String getSFileName() K 4QJDC8
{ HYyO/U9z|I
return sFileName; X^ckTIdR
} 8W#/=Xh?
?:vp3f#
9un]}7^
public void setSFileName(String value) n$ $^(-g@)
{ lqn7$
sFileName = value; B8UtD
} 5ppOG_
(9% ki$=}+
7yD=~l\Bbs
public int getNSplitter() M$~3`n*^
{ 91qk0z`N
return nSplitter; Ef{rY|E
} <cNXe4(
WSi`)@.XO
J(JsfU4
public void setNSplitter(int nCount) G3'>KMa.
{ fuSfBtLPR#
nSplitter = nCount; ^e:C{]S=
} +%Q:
} ,A`d!{]5
$}V<Um
zI$^yk-vn
/* &E0L7?l
**Utility.java 6E/>]3~!
*/ }IO<Dq=[
package NetFox; Se<]g$eK?5
jWJq[l
0<_|K>5dS|
public class Utility { :,gnOfV=
m^0r9y,
w`=_|4wFw
public Utility() rt%?K.S/
{ Ko_Sx.
'?=SnjMX
L9Sd4L_e
} BZq_om6
0T7(c-
//线程睡眠 !Ob
public static void sleep(int nSecond) %a=K:" oU[
{ I$/*Pt];
try{ ^]l^q'?>:
Thread.sleep(nSecond); PPk\W7G
} <~;;iM6
catch(Exception e) '{dduHo
{ *p:`F:
e.printStackTrace (); .Uq?SmK
} b~X^vXIv%%
} e8g"QDc
Lh3>xZy"-z
//日志 E .^5N~.
public static void log(String sMsg) f2Zi.?``H
{ 28FC@&'H
System.err.println(sMsg); cKuU#&FaV
} ?T=]?[
!+T\}1f7d
OLh`R]Sd
public static void log(int sMsg) |$"2R3
{ !$Aijd s5
System.err.println(sMsg); ]T|9>o!
} Xou1X$$z
} )OQhtxK
WeDeD\zy
maAZI-H{
/* {6{y"8
**TestMethod.java L08>9tf`
*/ Y$xO&\&)
package NetFox; jy@vz,/:%5
D`p&`]k3v
9rXbv4{
public class TestMethod { w}+#w8hu
x{4Rm,Dxn
8 2qf7`
public TestMethod() NbOeF7cq+
{ ///xx/weblogic60b2_win.exe j1_ E^
try{ j,%@%upM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xw_VK1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h4rIt3`
SiteFileFetch fileFetch = new SiteFileFetch(bean); vvA=:J4/i)
fileFetch.start(); (t&]u7Atr
} j.FA!4L
catch(Exception e){e.printStackTrace ();} } 8ZCWmd
5v"r>q[ X
uD4=1g6[s
} !`5[(lm
Td#D\d\R
V.zKjoky@
public static void main(String[] args) @sQ^6FK0G
{ +Qy*s1fit
new TestMethod(); ~3byAL
} 0#(K}9T)
} uC\FW6K=m
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