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)); tu{y
} %<8@NbF
for(int i=0;i<nEndPos.length-1;i++) jLRUWg
{ & c a-
nEndPos = nStartPos[i+1]; l8rBp87Q
} g|L" |Q
nEndPos[nEndPos.length-1] = nFileLength; ug47JW
} DWT4D)C,U
} TNs;#Q
7[aSP5e>T
$#E?`At{I
//启动子线程 <7Igd6u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sY,q*}SLD
for(int i=0;i<nStartPos.length;i++) ?L.c~w;l
{ iX ;E"ov]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nu|paA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^D`ARH
nStartPos,nEndPos,i); O :P%gz4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d9@!se9&Z
fileSplitterFetch.start(); 'fB/6[bd
} <tp\+v!u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _h;#\ )%~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~bL^&o(W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", haj\Dm
nEndPos = " + nFileLength); DxX333vC
// fileSplitterFetch[nPos.length-1].start(); ~]t/|xep
B1\@ n$
w s(9@
//等待子线程结束 7kbeAJ+{
//int count = 0; |%6zhkoufM
//是否结束while循环 %*4Gx +b
boolean breakWhile = false; )./pS~
cQj{[Wt4
){=2td$=$
while(!bStop) &j2fh!\4
{ #)im9LLC#
write_nPos(); SVvR]T&_
Utility.sleep(500); M+Rxt.~6
breakWhile = true; C/nzlp~
8p3pw=p
etbB;!6
for(int i=0;i<nStartPos.length;i++) ~i&Lc7Xl
{ K]q9wR'q
if(!fileSplitterFetch.bDownOver) bY6y)l
{ )2c[]d/a4
breakWhile = false; S].=gR0:
break; K%TlBKV
} !M]_CPh]
} {. r/tV5IH
if(breakWhile) DkO>?n:-C
break; |BysSJ
_SS6@`X
u#tLY/KA
//count++; 3e)3t`
//if(count>4) XO |U4#ya
// siteStop(); ti`R
} J?Kgev%
0q_Ol]<V
7QdU|1]
System.err.println("文件下载结束！"); 8e_ITqV%
} $~,]F
catch(Exception e){e.printStackTrace ();} A]nDI:pO|
} Y4PU~l
sePOW#|
|0Kj0u8T
//获得文件长度 G:qkk(6_#
public long getFileSize() -B\`O*Q
{ yQQ[_1$pq
int nFileLength = -1; #+Lo&%p#3
try{ ],%}}UN
URL url = new URL(siteInfoBean.getSSiteURL()); [MM11K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X/,4hjg
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Kx3G{5ja
fT.5@RR7^
JnX@eBNV
int responseCode=httpConnection.getResponseCode(); [ @>8Qhw
if(responseCode>=400) 5gq3 >qo
{ A0*u(15%
processErrorCode(responseCode); ilv6A9/
return -2; //-2 represent access is error |N[SCk>Kj
} 1{+Ni{
S<+_yB?
F'ZLN]"{
String sHeader; di6A.N5A
Ch ` Omq
8}p5MG
for(int i=1;;i++) <wTkPErUG
{ ,)+O.Lf7&.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M38,SH<
//Utility.log(in.readLine()); R{.wAH(
sHeader=httpConnection.getHeaderFieldKey(i); Qwx}e\=
if(sHeader!=null) ?,|_<'$4T
{ C<A82u;t%@
if(sHeader.equals("Content-Length")) z'r.LBnh
{ VIbm%b$~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xtU)3I=F%
break; ;3'}(_n
} V]}/e!XK\
} `A80""y:M
else X%,;IW]a
break; _*Vq1D]C
} > ^3xBI:Q
} 7w)#[^
catch(IOException e){e.printStackTrace ();} Yl1@gw7
catch(Exception e){e.printStackTrace ();} ZvNXfC3Ia
=]7|*-
c#9 zw[y-L
Utility.log(nFileLength); KnZm(c9+
=KT7ZSTV
OR&+`P"-\
return nFileLength; ika{>hbH
} \{?v|%n=/i
ycw'>W3.*
ZH:#~Zyj
//保存下载信息（文件指针位置） iG!MIt*
private void write_nPos() WP^%[?S2
{ e5fJN)+a
try{ 1aYO:ZPy
output = new DataOutputStream(new FileOutputStream(tmpFile)); L6$,<}l
output.writeInt(nStartPos.length); =sG(l
for(int i=0;i<nStartPos.length;i++) P9`i6H'~
{ #_7}O0?c3
// output.writeLong(nPos); WF-imI:EK
output.writeLong(fileSplitterFetch.nStartPos); -lSm:O@'
output.writeLong(fileSplitterFetch.nEndPos); [W{`L_"
} o?{VGJH<v
output.close(); "@`mPe/
} WKxJ`r\
catch(IOException e){e.printStackTrace ();} IRo[|&c
catch(Exception e){e.printStackTrace ();} 0?,EteR
} J+DuQ;k;
" I`YJEv
=K8`[iH
//读取保存的下载信息（文件指针位置） 1ygu>sKS&A
private void read_nPos() WHAEB1c#Q
{ HEe0dqG
try{ x6Z$lhZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qLYv=h$,
int nCount = input.readInt(); _rjCwo\
nStartPos = new long[nCount]; RSmxwx^
nEndPos = new long[nCount]; HTx7._b
for(int i=0;i<nStartPos.length;i++) Y,E:?
{ k7y!!AV
nStartPos = input.readLong(); ?Cu#(
nEndPos = input.readLong(); 8-8= \
} ]s,T` (&
input.close(); 4TR:bQZs
} 6oUT+^z#
catch(IOException e){e.printStackTrace ();} v/yk T9@;
catch(Exception e){e.printStackTrace ();} i@B5B2
} 3'&]v6|
E?08=$^5%
7^Onq0ym T
private void processErrorCode(int nErrorCode) \D}/tz5~B
{ u4+VG5.rhT
System.err.println("Error Code : " + nErrorCode); |Z2_1( ku
} /[EI0~P
R!$j_H
Hh!x&;x}
//停止文件下载 j<L!ONvJ1
public void siteStop() dd4yS}yBlR
{ kP;Rts8JD
bStop = true; Vl9\&EL
for(int i=0;i<nStartPos.length;i++) 54}s:[O
fileSplitterFetch.splitterStop(); HmX(=Y
j@9nX4Z
$~ItT1k_
} >/'WU79TYE
} HVu_@[SYR3
//负责部分文件的抓取 T@Q.m.iV4
**FileSplitterFetch.java }){hQt7
*/ t<:XY
package NetFox; cIgFSwQ4
)O7Mfr
{ZfTUt)-P
import java.io.*; ^Y'>3o21f
import java.net.*; vk#xCggK
#vS>^OyP
jliKMd<?
public class FileSplitterFetch extends Thread { E|^a7-}|
aMj3ov8p
R(q fP
String sURL; //File URL cc^V~-ph
long nStartPos; //File Snippet Start Position ,e,fOL
long nEndPos; //File Snippet End Position v1)jZ.:
int nThreadID; //Thread's ID j4NS5
boolean bDownOver = false; //Downing is over LL,~&5{
boolean bStop = false; //Stop identical fitm*
FileAccessI fileAccessI = null; //File Access interface a!>AhOk.
^R2:Z&Iv%
'{Ywb@Bc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K):)bL(B
{ M=!x0V;
this.sURL = sURL; rP>5OLP
this.nStartPos = nStart; %Y!lEzB5
this.nEndPos = nEnd; lFRgyEPH
nThreadID = id; / ?Q@Pn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5$O@+W!?@
} pWQ?pTh
Y#rao:I
Li7/pUq>}!
public void run() {cG&l:-r
{ jdoI)J@9H
while(nStartPos < nEndPos && !bStop) _/PjeEm $p
{ 8~4{e,} ,
^LnCxA&QH
0gnr@9,X
try{ ~>qcV=F^d,
URL url = new URL(sURL); [zY9"B<3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WMYvE\"
httpConnection.setRequestProperty("User-Agent","NetFox"); b ~F85U2
String sProperty = "bytes="+nStartPos+"-"; _\u'~wWl
httpConnection.setRequestProperty("RANGE",sProperty); G:A` n;E0
Utility.log(sProperty); ZgzrA&6
[Si`pPvl
B?Pu0 _|s
InputStream input = httpConnection.getInputStream(); !$&K~>`
//logResponseHead(httpConnection); Z}XA(;ck
,@GI3bl
J/)Q{*`_
byte[] b = new byte[1024]; /J5wwQ (:
int nRead; _%.atW7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]V}";cm;2
{ cp]\<p('A
nStartPos += fileAccessI.write(b,0,nRead); 6R"& !.ZF
//if(nThreadID == 1) Y2Y/laD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x.}iSE{
} Xi$uK-AHpj
tX6n~NJ$
%m{h1UQQ+
Utility.log("Thread " + nThreadID + " is over!"); hoPCbjkov
bDownOver = true; lKwIlp
//nPos = fileAccessI.write (b,0,nRead); `43E-'g
} z!?xz
catch(Exception e){e.printStackTrace ();} (i&:=Bfn)
} 4fp}`U
} CSIW|R@
I+ydVj(Op
~#OnA1)
//打印回应的头信息 EtKy?]i
public void logResponseHead(HttpURLConnection con) Wc#4%kT
{ U H `=
for(int i=1;;i++) uBH4E;[f
{ Pe~[qETv
String header=con.getHeaderFieldKey(i); 51l:
if(header!=null) THkg,*;:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); arET2(h
Utility.log(header+" : "+con.getHeaderField(header)); Jro)
else J?LetyDNr]
break; =J<3B H^m
} <Y9e n!3\
} 9x23## s
~"#qG6dP
sA#}0>`3S
public void splitterStop() Y'mtMLfMc
{ ^e1@o\]
bStop = true; RG0kOw0
} !%?O`+r
fX2sjfk
<Y:{>=
} pE,2pT2>
=+DfIO
oIrO%v:'!
/* )%dxfwd6
**FileAccess.java g]vo."}5E
*//文件访问(定位，写) u%!/-&?wF
package NetFox; 3K!(/,`
import java.io.*; ($'W(DH4
J}BN}|Y@2
9sG]Q[:.]
public class FileAccessI implements Serializable{ %PM&`c98z7
ct`j7[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~@=(#tO.
RandomAccessFile oSavedFile; q=(% ]BK
long nPos; G!dx)v
cD6S;PSg
KW-GVe%8f
public FileAccessI() throws IOException 0v+-yEkw
{ 2[j(C
this("",0); % bfe_k(
} ZP{<f~;
DK)T2{:
5(>SFxz"t
public FileAccessI(String sName,long nPos) throws IOException }D>#AFs6#
{ P q0%oz
oSavedFile = new RandomAccessFile(sName,"rw"); ja^_Lh9
this.nPos = nPos; Yw] 7@
oSavedFile.seek(nPos); p<1y$=zS
} i/j53towe
3ew4QPT'
L4,b ThSG
public synchronized int write(byte[] b,int nStart,int nLen) n,U?]mr
{ /sfJ:KP0
int n = -1; |Dt_lQp#
try{ o?Aj6fNY?
oSavedFile.write(b,nStart,nLen); &1(- 8z*
n = nLen; <d @9[]
} o^XDG^35`
catch(IOException e) 2n)?)w]!M
{ * xCY^_
e.printStackTrace (); C];P yQS
} 8N%nG( 0
0j_kK
`^52IkM)
return n; 7:,f|>
} ~wa6S?
_0(%^5Y
K>dB{w#gS
} 3P9ux
#MKM.T,\t
1rJ2}d\y
/* 4vEP\E3u<j
**SiteInfoBean.java d2V X\
*/ U@M3.[jw
package NetFox; RFMPh<Ac
#8|LPfA
d{"-iw)t
public class SiteInfoBean { qT48Y
_]-4d_&3(
%8,$ILN
private String sSiteURL; //Site's URL 4b:|>Z-
private String sFilePath; //Saved File's Path 0?<#!
private String sFileName; //Saved File's Name *!%lBt{2
private int nSplitter; //Count of Splited Downloading File IdQ./@?
t N{S;)q#X
z Fo11;*D
public SiteInfoBean() lj (y
{//nSplitter的缺省值为5 P(hGkY=(
//default value of nSplitter is 5 G18w3BFx
this("","","",5); }5-w,m{8/
} GC{M"q|_
X` zWw_i
64<;6*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y !?'[t
{ 93>4n\
sSiteURL= sURL; TaN{xpo
sFilePath = sPath; %up?70
sFileName = sName; K]hp-QK<
this.nSplitter = nSpiltter; }d<R 5
,~1"50 Hp@
Y()"2CCV
} FQ]/c#J
iRzFA!wH
,%M[$S'
public String getSSiteURL() k, HC"?K
{ wDJ`#"5p{
return sSiteURL; u^1#9bAW8
} lN,?N{6s
"8xAe0-4
8]ZzO(=@{
public void setSSiteURL(String value) .Q{RTp
{ A&Y5z[p
sSiteURL = value; \D7bTn
} X@rA2);6
*doNPp)m
<$A,Ex94
public String getSFilePath() 3v/B*M VI
{ ghk=` !yKw
return sFilePath; JvpGxj
} =<HDek
9iA rBL"
S+ kq1R
public void setSFilePath(String value) Cn{Hk)6
{ gcJ!_KZK
sFilePath = value; Nep4J;
} mdj%zJ8/
eb62(:=N6
Zf'*pp T&q
public String getSFileName() 6':iW~iI
{ jD: N)((
return sFileName; +yGQt3U
} '![oLy
1Kg0y71"
d1b]+AG4
public void setSFileName(String value) =Zd(<&B K
{ : T*Q2
sFileName = value; "-J5!y*,Y
} kv+%
4,9$udiGY
$Ome]+0
public int getNSplitter() ,X4e?$7g
{ O$Rz/&
return nSplitter; .tngN<f
} 8>Cr6m
YH&=cI@
~>2uRjvkwB
public void setNSplitter(int nCount) uqMw-f/
{ "yWw3(V2>
nSplitter = nCount; i5,iJe0cA
} |Splbsk
} +vBi7#&
+$2{u_m,
?,} u6tH
/* T]#V
**Utility.java zLI0RI.Pe
*/ ZnG.::&:
package NetFox; 2MkrVQQ9g
)vp0X\3q`
O%bbyR2
public class Utility { 55[ 4)*
.tBlGMcN
Q8p6n
public Utility() Z>[7#;;
{ T1LYJ]5
1+l8%G=hB
aZfMeW
} L@}PW)#
>lI7]hbIs
//线程睡眠 b}e1JPk}!
public static void sleep(int nSecond) Q&9yrx.
{ &C 9hT
try{ =ily=j"hK
Thread.sleep(nSecond); X>q`F;W
} mxc)Wm<4
catch(Exception e) fi+}hGj(r
{ h Yu6PWK
e.printStackTrace (); iD^,O)b
} ^X#y'odtbS
} PEMkx"h+
@[GV0*yz$
//日志 )rc!irac]
public static void log(String sMsg) Ni$'# W?t
{ |tXA$}"L8
System.err.println(sMsg); NOb`)qb
} qJey&_
Rr) 5[
j=\h|^gA
public static void log(int sMsg) -,bFGTvYQ
{ nt.LiM/L
System.err.println(sMsg); H]TdW;ZbZ
} l|5 h
} 1S{Biqi+
UwN Vvo
"*g+qll!5d
/* bR\7j+*&
**TestMethod.java qxL\G &~
*/ bS_#3T
package NetFox; spK8^sh
WBe0^=x
UG| /Px ]
public class TestMethod { 0<M-asI?
2"/MM2s
6[bopin
public TestMethod() 0G%9 @^B
{ ///xx/weblogic60b2_win.exe hfB$4s9
try{ ' jciX]g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q'3{M]Tk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rPxRGoR
SiteFileFetch fileFetch = new SiteFileFetch(bean); >w,L=z=
fileFetch.start(); ]8G 'R-8}
} I&PJ[U#~a
catch(Exception e){e.printStackTrace ();} zzmC[,u}
Mz+I YP`L
,@$5,rNf
} JsaXI:%1
# :+Nr
unDW2#GX
public static void main(String[] args) !j~wAdHk
{ I}$`gUXX8x
new TestMethod(); MT6p@b5
} *,u3Wm|7
} {i;,Io7W
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