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)); 5}^08Xl
} L5|;VH
for(int i=0;i<nEndPos.length-1;i++) SE-, 1p
{ K~~*M?.Z
nEndPos = nStartPos[i+1]; cw-JGqLx
} `0vy+T5
nEndPos[nEndPos.length-1] = nFileLength; KdQ|$t
} FbNQ
} ^WYG?/{4
bIl0rx[`
]]QCJf@p
//启动子线程 {_N(S]Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4)Wzj4qW
for(int i=0;i<nStartPos.length;i++) -OGy-"
{ #UnO~IE.m$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zSufU2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +A3\Hj&W
nStartPos,nEndPos,i); .8xacVyK2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ox1QP2t6Y
fileSplitterFetch.start(); 8n p>#V
} *ww(5 t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [#fqyg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $<DA[ %pv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FNRE_83
nEndPos = " + nFileLength); Q6<Uuiw
// fileSplitterFetch[nPos.length-1].start(); >l*9DaZ
y(BLin!O.
e$|)wOwU
//等待子线程结束 fe`G^hV
//int count = 0; i]WlMC6
//是否结束while循环 jsht2]iq3K
boolean breakWhile = false; gG>^h1_o~
?PtRb:RHt
-^yc yZ
while(!bStop) 1ORi]`
{ /'^>-!8_1
write_nPos(); tl#s:
Utility.sleep(500); 6y!?xot
breakWhile = true; L. ?dI82c
gx R|S
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for(int i=0;i<nStartPos.length;i++) m&c(N
{ \(t>(4s_~
if(!fileSplitterFetch.bDownOver) $6%;mep
{ 9rc n*sm
breakWhile = false; j@\/]oL^We
break; k$- q;VI
} Eu~wbU"%
} rZ4<*Zegv
if(breakWhile) T1[ZrY'0
break; "<R 2oo)^
|VF"Cjw?
X,CFY
//count++; LMj'?SuH
//if(count>4) nECf2>Yp v
// siteStop(); ;P#*R3
} tO;W?g
ofv 1G=P
PX/0 jv
System.err.println("文件下载结束！"); ?2>v5p
} .Sw'Bo!Ee
catch(Exception e){e.printStackTrace ();} =xP{f<`
} .Q@'Ob`
zhL,BTH
?E@[~qq_
//获得文件长度 "$YLU}S9
public long getFileSize() =i %w_e
{ RL8wSK
int nFileLength = -1; ZJM^P'r.1c
try{ Bq`kVfx
URL url = new URL(siteInfoBean.getSSiteURL()); <cjTn:w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aBLb i
httpConnection.setRequestProperty("User-Agent","NetFox"); L#bQ`t
ay[*b_f
M&-/&>n!
int responseCode=httpConnection.getResponseCode(); "A3xX&9-q
if(responseCode>=400) l_EI7mJ
{ A2S9h,t
processErrorCode(responseCode); S*:w\nXP~
return -2; //-2 represent access is error >ON.ftZi
} ]iX$p~riH
Rj=Om
DlO;EH
String sHeader; (LPD
S`.-D+.68
6[7k}9`alz
for(int i=1;;i++) IQv>{h}
{ F'*4:WD7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); - mXr6R?
//Utility.log(in.readLine()); {mGWMv
sHeader=httpConnection.getHeaderFieldKey(i); n/D]r
if(sHeader!=null) }Cf[nGh|B
{ M lwQ_5O
if(sHeader.equals("Content-Length")) h]9^bX__Z
{ &|] ^ u/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W{aNS@1
break; c>.Xc[H
} Lcm!e
} v21?
else ~Wv?p4
break; !~v>&bCG>9
} Z8UM0B=i
} -C<aB750O)
catch(IOException e){e.printStackTrace ();} Wno5B/V
catch(Exception e){e.printStackTrace ();} 5!*a,$S
q>X2=&1
D3ad2vH
Utility.log(nFileLength); 4F!d V;"Z(
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(0f^Hh wF
return nFileLength; iq-o$6Pg
} M+:wa@Kl
t68RWzqiG[
1fZ:^|\
//保存下载信息（文件指针位置） 1YL5 ![T
private void write_nPos() IrC=9%pd$R
{ L;`t%1
try{ K4~Ox
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5Bo)j_Qo
output.writeInt(nStartPos.length); Fwqf4&/
for(int i=0;i<nStartPos.length;i++) 9f`Pi:*+/
{ yjzNU5F
// output.writeLong(nPos); Xi.?9J`@
output.writeLong(fileSplitterFetch.nStartPos); ]+P&Y:
output.writeLong(fileSplitterFetch.nEndPos); W9"I++~f
} =ndKG5
output.close(); ak[)+_k_
} TVA1FD
catch(IOException e){e.printStackTrace ();} O6]~5&8U.
catch(Exception e){e.printStackTrace ();} gG>>ynn
} AF6'JxG7
^EOjq
@35shLs
//读取保存的下载信息（文件指针位置） wP*Z/}Uum+
private void read_nPos() b??1Up
{ (P-<9y@
try{ K2 2Xo<3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g_U69 z
int nCount = input.readInt(); s=4.Ovd\
nStartPos = new long[nCount]; +&@0;zSga
nEndPos = new long[nCount]; KG$2u:n
for(int i=0;i<nStartPos.length;i++) ig{5]wZ(
{ |{T2|iJI
nStartPos = input.readLong(); }__+[-
nEndPos = input.readLong(); A$cbH.
} _L":Wux
input.close(); bSfQH4F
} HenJlo
catch(IOException e){e.printStackTrace ();} ~@lNBF
catch(Exception e){e.printStackTrace ();} X[<9+Q-&
} at!?"u
~@JC1+
<h({+N
private void processErrorCode(int nErrorCode) L%FL{G
{ #ZA YP
System.err.println("Error Code : " + nErrorCode); 30@ GFaab
} ^dqEOW
9&cZIP
[@6iStRg7
//停止文件下载 j$6}r
public void siteStop() WmA578|l!
{ <X?F :?Mk
bStop = true; +zsya4r
for(int i=0;i<nStartPos.length;i++) $]FWpr%)
fileSplitterFetch.splitterStop(); n9fk{"y'G
MXb(Z9)]kw
|k+^D:
} x<(h9tB
} JN_# [S$
//负责部分文件的抓取 *C\O]r:'
**FileSplitterFetch.java }kpkHq"`f
*/ &^.'g{\Y
package NetFox; g5)VV"
iweP3u##
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import java.io.*; $4&Ql
import java.net.*; ~"k'T9QBY
D6w0Y:A{.
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public class FileSplitterFetch extends Thread { ry'(mM
Lmb<)YY
\IKr+wlN8
String sURL; //File URL (Gcl,IW
long nStartPos; //File Snippet Start Position cc[w%jlA#
long nEndPos; //File Snippet End Position yWzTHW`)Mr
int nThreadID; //Thread's ID Zu,f&smb
boolean bDownOver = false; //Downing is over *D,T}N
boolean bStop = false; //Stop identical E'Bt1u
FileAccessI fileAccessI = null; //File Access interface jkq+j^
a;K:~R+@,
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P]n 'q
{ S~T[*Z/m
this.sURL = sURL; X6)LpMm
this.nStartPos = nStart; SpgVsz
this.nEndPos = nEnd; ^|Y!NHYH$Z
nThreadID = id; -LyIu#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ze-iDd_y
} T1E{NgK
L" o6)N
nV,a|V5Xm
public void run() ;c`B'
{ `d8TA#|`
while(nStartPos < nEndPos && !bStop) /y}
{ V+^\SiM
v,jU9D\
J?&9ofj&
try{ r$KDNa$/a
URL url = new URL(sURL); y;;@T X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :9<5GF(
httpConnection.setRequestProperty("User-Agent","NetFox"); L-XTIL$$
String sProperty = "bytes="+nStartPos+"-"; S'txY\
httpConnection.setRequestProperty("RANGE",sProperty); R`c5-0A
Utility.log(sProperty); 4T:ZEvdzf
4Xz|HU?
_#+i;$cO-X
InputStream input = httpConnection.getInputStream(); %X3T<3<
//logResponseHead(httpConnection); D<MtLwH
&b_duWs
"k.<"pf
byte[] b = new byte[1024]; jzQgDed ]
int nRead; 1n^xVk-G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fq8Z:;C8
{ Jps!,Mflc
nStartPos += fileAccessI.write(b,0,nRead); i|t$sBIh
//if(nThreadID == 1) q45n.A6a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z8oSh t`+
} ;.iy{&$
5q\]]LV>
TtzB[F
Utility.log("Thread " + nThreadID + " is over!"); ?1YK-T@
bDownOver = true; Q8_d]V=X:
//nPos = fileAccessI.write (b,0,nRead); Q-\: u~
} #u~8Txt
catch(Exception e){e.printStackTrace ();} R#0UwRjeF
} %n^]1R#
} #r\uh\Cy
=#W6+=YN8
v"j7},P@
//打印回应的头信息 L(.5:&Y=`
public void logResponseHead(HttpURLConnection con) k20tn ew
{ n'SnqJ&}
for(int i=1;;i++) dQ<EDtap
{ ^Kn}{m/3Y
String header=con.getHeaderFieldKey(i); "h "vp&A
if(header!=null) hGsYu)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^W^%PJD|
Utility.log(header+" : "+con.getHeaderField(header)); (UCWSA7oc
else oZQu&O'
break; hT<v8
} Z',pQ{rD
} 7>#74oy
d4lEd>Ni
N)QW$iw9
public void splitterStop() @sP?@<C
{ WkT4&|POJ
bStop = true; ;e+ErN`a.~
} 4XRVluD%W.
a$ Z06j
=cxjb,r
} SJ<nAX
0L'h5i>H)
O[!]/qP+.
/* 4g|}]K1s
**FileAccess.java FbF P
*//文件访问(定位，写) (f7R~le
package NetFox; &T{+B:*v
import java.io.*; yJ?6BLJi
~x2azY2DP
d;K,2
public class FileAccessI implements Serializable{ W+e
ikUG`F%W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8< R#}
RandomAccessFile oSavedFile; W_%Dg]l
long nPos; 6:H@=fEv
%5'6^bT
tks1*I$S<
public FileAccessI() throws IOException &4LrV+`$V
{ yTv#T(of
this("",0); L:7%Wdyh
} 3{CXIS
p~qdkA<
"~XAD(T6
public FileAccessI(String sName,long nPos) throws IOException alyWp
{ ol-U%J
oSavedFile = new RandomAccessFile(sName,"rw"); 3:s!0ty"
this.nPos = nPos; G22u+ua
oSavedFile.seek(nPos); 'vBuQinn
} o^mW`g8[
#>}cuC@
t~3!| @3i
public synchronized int write(byte[] b,int nStart,int nLen) `$05+UU
{ H+` Zp
int n = -1; jx J5F3d
try{ nwf(`=TC
oSavedFile.write(b,nStart,nLen); (V&$KDOA
n = nLen; xtyOG
} ^tI ,eZ
catch(IOException e) `Ps&N^[
{ ?|kwYA$4o
e.printStackTrace (); Ch>r.OfP
} )m|)cLT&
f]Xh7m(Gh
UZz/v#y~
return n; `fS$@{YI_
} ]@0C1r
)1N~-VuT
2)-Umq{]{
} |cs]98FEf
9!;/+P
0-6rIdDTM
/* "\3C)Nz?
**SiteInfoBean.java Qu|H_<8g
*/ ;0FfP
package NetFox; ,N93H3(
$i1$nc8
wNtC5
public class SiteInfoBean { :<hM@>eFn
#A\@)wJ
{\hjKP
private String sSiteURL; //Site's URL f3^Anaa]l
private String sFilePath; //Saved File's Path *PM#ngLX}r
private String sFileName; //Saved File's Name ]lqLC
private int nSplitter; //Count of Splited Downloading File DHQS7%)f`
xa8;"Y~"bg
VYbH:4K@%
public SiteInfoBean() ^,}1^?*
{//nSplitter的缺省值为5 zcGmru|k
//default value of nSplitter is 5 a`I \19p]
this("","","",5); XlLG/N
} a@!(o )>
o, PpD,,
?.Q$@Ih0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {>g{+Eq
{ ia@ |+r
sSiteURL= sURL; Z-:T')#Cf
sFilePath = sPath; @CMEmgk~
sFileName = sName; "zj[v1K9-A
this.nSplitter = nSpiltter; > 9.%hSy
V_zU?}lZ^
V/`vX;%
} jh(T?t$&
jIEntk
G>=Fdt7Oc
public String getSSiteURL() 9A~w2z\G
{ rtNYX=P
return sSiteURL; iYD5~pK8
} e.\dqt~%y
<p/zm}?')
DG?g~{Y~b
public void setSSiteURL(String value) t'1g+g
{ bFjH*~ P
sSiteURL = value; pu~b\&^G
} ,oykOda:|
(@->AJF1\
PriLV4?
public String getSFilePath() JR8|!Of@B
{ x$;RfK2&p
return sFilePath; i-PK59VZ8f
} Bv<aB(c
Qk? WX (`B
k4a51[SYBK
public void setSFilePath(String value) `WIZY33V
{ z%S$~^=b
sFilePath = value; Q3Pu<j}Y
} G9NI`]k
h4jo<yp\
>$7x]f
public String getSFileName() }4N'as/ZO
{ Z#.1p'3qm1
return sFileName; EB| iW2'
} :.4O Hp1
^3[_4av
3m= _a
public void setSFileName(String value) b"WF]x|^
{ -'Ay(h
sFileName = value; &#L C'
} D6Au)1y=&
Vm|KL3}NRv
,VS(4
public int getNSplitter() <Y."()}GeH
{ E447'aJ
return nSplitter; 5mQ@&E~#W
} ?HJh;96B
KF zI27r
PJiU2Y33
public void setNSplitter(int nCount) %ggf|\-e
{ 1l$2T y+ =
nSplitter = nCount; "h#R>3I1)
} *#'j0;2F
} g!R7CRt%
p;>A:i
:~ pGHl
/* &EqLF
**Utility.java /1MmOB
*/ 7b+r LyS0
package NetFox; U xBd14-R_
r5DRF4,7
V_:`K$
public class Utility { HD^#"
?>Sv_0
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public Utility() wkM1tKhy/
{ /QY F|%7!
iqvLu{
S[1<Qrv]
} Up{[baWF
:D*U4< /u
//线程睡眠 =..Bh8P71!
public static void sleep(int nSecond) aOH|[
{ ^K;k4oK
try{ EY)2,
Thread.sleep(nSecond); Jqj!k*=/
} H:@hCO[a
catch(Exception e) zbmC?2$
{ Z+&V >
e.printStackTrace (); +P^ ;7"H
} #73pryXV
} {1)A"lQu
w}gmVJ#p
//日志 `Gqe]ZE#"
public static void log(String sMsg) <Z]#vrq
{ "E(i<
System.err.println(sMsg); o/w3b8
} 6;Z-Y>\c
+4s]#{mP
$Z:O&sD{
public static void log(int sMsg) SXk.7bMV6
{ k ucbI_
System.err.println(sMsg); Kcm+%p^
} 6nZ]y&$G-k
} Ipk;Nq
S MWXP
KLyRb0V
/* 5MVa;m
**TestMethod.java CIx(SeEF
*/ {Rkd;`Q`!
package NetFox; lS4rpbU_
?H=q!i
m\56BP-AM
public class TestMethod { 5dePpFD5
~w?02FU
e$J>z {
public TestMethod() C^L+R7
{ ///xx/weblogic60b2_win.exe M]s\F(*ib
try{ pR61bl)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Z]Wj9iY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ij ?7MP
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'XK 'T\m
fileFetch.start(); g&s. 0+
} N1$u@P{
catch(Exception e){e.printStackTrace ();} ,^:{!?v
$-}&RW9
%T({;/
} Sc7 Ftb%
4j={ 9e<
V4[-:k
public static void main(String[] args) !Y ,7%
{ AS7L
new TestMethod(); Az&>.*
} ev4[4T-(@
} $Zu?Gd?
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