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)); O*7Gl G
} /_G^d1T1?L
for(int i=0;i<nEndPos.length-1;i++) ,5L[M&5
{ qhiO( !jK
nEndPos = nStartPos[i+1]; OAiip,
} g0BJj=
nEndPos[nEndPos.length-1] = nFileLength; )cX6o[oia
} X3j<HQcK
} j3`"9bY
1"Z61gXrz
gM<*(=x'
//启动子线程 $'2yPoR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p;VHg
for(int i=0;i<nStartPos.length;i++) L3g}Z1<!$
{ Tv{X$`%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O1_dA%m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Jj$N3UCg7
nStartPos,nEndPos,i); ch%-Cg~%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;w_f^R #
fileSplitterFetch.start(); mnM!^[|z
} C4jqT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aI6fPQe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ['SZe0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", okO^/"
nEndPos = " + nFileLength); g0!{CW
// fileSplitterFetch[nPos.length-1].start(); Uxq9H
cH!w;Ub]
{)QSxO
//等待子线程结束 *MEDV1l_T
//int count = 0; n"1LVJN7
//是否结束while循环 z5G$'
boolean breakWhile = false; clZjb
0{PRv./`
p/a)vN+*x'
while(!bStop) B>CG/]
{ <d\Lvo[
write_nPos(); 9)a:8/Y
Utility.sleep(500); /k(KA [bS
breakWhile = true; "c6(=FFq
6-@ X
JPX5Jm()
for(int i=0;i<nStartPos.length;i++) CR-6}T
{ )PU?`yLTr
if(!fileSplitterFetch.bDownOver) #UcqKq
{ +([ iCL
breakWhile = false; D4x~Vk%H
break; x*A_1_A
} $~V,.RD
} 'ju{j`b
if(breakWhile) Rmrv@.dr!
break; >!vb;a!
B!=JRfT
y/ #{pyJ
//count++; *jps}uk<
//if(count>4) RfMrGC^?
// siteStop(); (P-Bmu!s
} {:VUu?5-t;
(YbRYu
S[bFS7[
System.err.println("文件下载结束！"); :h>d'+\
} \B'rWk33,
catch(Exception e){e.printStackTrace ();} AiT&:'<UT
} (1r.AG`g
L+}q !'8S
ptS1d$
//获得文件长度 )vFJx[a<n`
public long getFileSize() wj fk >
{ jrMY]Ea2`
int nFileLength = -1; p=Nord
try{ ubn`w=w$
URL url = new URL(siteInfoBean.getSSiteURL()); 3%<Uq%pJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L,&R0gxi
httpConnection.setRequestProperty("User-Agent","NetFox"); H*DWDJxmV
:RsO$@0G
tH_e?6]
int responseCode=httpConnection.getResponseCode(); X`dd"8%
if(responseCode>=400) |=7ouFl
{ K; 7o+Xr
processErrorCode(responseCode); (LW4z8e#
return -2; //-2 represent access is error 0ivlKe%
} %=:*yf>}
/-ebx~FX&
eGZX6Q7m
String sHeader; *[Ld\lRj
g7*ii X
l^s\^b=W
for(int i=1;;i++) Hz}6XS@
{ AHq;6cG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .!ThqYo
//Utility.log(in.readLine()); { jnQoxN
sHeader=httpConnection.getHeaderFieldKey(i); '2u(fLq3h
if(sHeader!=null) xS) njuq4
{ }t tiL
if(sHeader.equals("Content-Length")) |fMjg'%{}
{ c5K@<=?,E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =_%i5]89P
break; 8]6u]3q#
} EK^B=)q6:W
} ;- D1n
else 9]AiaV9
break; biCX:m+_?
} i,Yq oe`
} _c=[P@
catch(IOException e){e.printStackTrace ();} h&3*O[`
catch(Exception e){e.printStackTrace ();} <_HK@E<_HO
gO*:<B g
v$R+5_@[l
Utility.log(nFileLength); FhZ^/= As
as1ZLfN.
(nk)'ur.
return nFileLength; D-7PO3F:F
} oT7=
SbNs#
>:whNp
//保存下载信息（文件指针位置） "HRoS#|\
private void write_nPos() )$#]h]ac
{ OW(45
try{ cTO\Vhg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8Wn;U!qT
output.writeInt(nStartPos.length); wN[mU
for(int i=0;i<nStartPos.length;i++) ;2||g8'
{ -2}-;|
// output.writeLong(nPos); '-sAi
output.writeLong(fileSplitterFetch.nStartPos); En:.U9?X
output.writeLong(fileSplitterFetch.nEndPos); ~n:dHK`
} ~$1Zw&X
output.close(); 6#S}EaWf
} bI)ItC_wf!
catch(IOException e){e.printStackTrace ();} (f DA
catch(Exception e){e.printStackTrace ();} E|ce[|2
} 60KhwD1
tAfdbt
xtef18i>
//读取保存的下载信息（文件指针位置） 1Ih.?7}
private void read_nPos() K1rF;7Y6
{ ;=IC.<Q<}
try{ $d1+d;Mn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jd9GueV*(
int nCount = input.readInt(); -LF0%G
nStartPos = new long[nCount]; +u1meh3u
nEndPos = new long[nCount]; 7\sJ=*
for(int i=0;i<nStartPos.length;i++) D8a[zXWnc
{ 5BvCP
nStartPos = input.readLong(); DPuz'e*
nEndPos = input.readLong(); (VYY-%N`
} zGrUl|j
input.close(); / ,3,l^kZ
} 6Q<^,`/T
catch(IOException e){e.printStackTrace ();} [AzQP!gi
catch(Exception e){e.printStackTrace ();} i{8T 8
} 8*rd`k1|g
d\aarhD8*
pK=$)<I"6
private void processErrorCode(int nErrorCode) 90)0\i+P
{ \Q+9sV 5,[
System.err.println("Error Code : " + nErrorCode); V[f-Nj Kf
} +u%^YBr
F|K=].
rn^7B-V
//停止文件下载 O>)<w Ms`
public void siteStop() 2}Dd{kC-
{ >C"f'!oM,j
bStop = true; 8d9&LPv
for(int i=0;i<nStartPos.length;i++) k=,,s(]tx
fileSplitterFetch.splitterStop(); /.<tC(
0HUSN_3F
%c%0pGn8-
} =[8EQdR
} `Tt}:9/3
//负责部分文件的抓取 :'aT4
**FileSplitterFetch.java .Ap-<FB
*/ 5~T`R~Uqb
package NetFox; BKDs3?&
{9sA'5
\|20E51B[
import java.io.*; `oP<mLxle
import java.net.*; ^|^ek
:34#z.O
;seD{y7!
public class FileSplitterFetch extends Thread { %4#,y(dO
NvH9?Ek"
m1x7f%_
String sURL; //File URL ,lX5-1H
long nStartPos; //File Snippet Start Position VuqN)CE^Uq
long nEndPos; //File Snippet End Position zx"'WM*
int nThreadID; //Thread's ID O$jj&
boolean bDownOver = false; //Downing is over /C(lQs*l
boolean bStop = false; //Stop identical .'o<.\R8
FileAccessI fileAccessI = null; //File Access interface E~?0Yrm F
"dfq
"p>$^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NNZ%jJy?=,
{ ":E^&yQ
this.sURL = sURL; m+p}Qi8i)
this.nStartPos = nStart; !g}?x3
this.nEndPos = nEnd; [(v?Z`cX\
nThreadID = id; %2Q:+6)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =;DmD?nZ
} Le3H!9lbc
,i>u>YNZ
3-cCdn
public void run() }ge~Nu>w
{ 1qWIku
while(nStartPos < nEndPos && !bStop) 0yW#).D^b
{ O]{3aMs!Y
VU+`yQp
IXb]\ )
try{ } ).rD
URL url = new URL(sURL); mG4myQ?$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,at"Q$)T
httpConnection.setRequestProperty("User-Agent","NetFox"); n< UuVu
String sProperty = "bytes="+nStartPos+"-"; [.\uHt
httpConnection.setRequestProperty("RANGE",sProperty); Df;EemCh
Utility.log(sProperty); >|%dN jf@Q
RUcpdeo
/]H6'
InputStream input = httpConnection.getInputStream(); "]M:+mH{]
//logResponseHead(httpConnection); _2Sb?]Xn
3xS+Pu\)
utIR\e#:B
byte[] b = new byte[1024]; ~(E.$y7P
int nRead; j)4:*R.Z]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O@;;GJ
{ =zw=Jp
nStartPos += fileAccessI.write(b,0,nRead); ~jdvxoX-
//if(nThreadID == 1) -dXlGOD+C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m0xL'g6F
} =O= 0 D
:s8^nEK
K)z{R n
Utility.log("Thread " + nThreadID + " is over!"); , 'WhF-
bDownOver = true; VOc_7q_=
//nPos = fileAccessI.write (b,0,nRead); C!KxY/*Px
} +<5q8{]Pk
catch(Exception e){e.printStackTrace ();} f,QoA
} "`P/j+-rt
} `#O%ZZ+
ML6Y_|6 |
H;('h#=cD
//打印回应的头信息 )?35!s6
public void logResponseHead(HttpURLConnection con) AF ,*bb
{ HUF],[N
for(int i=1;;i++) Tb~|p_;o
{ B/"TaXVU
String header=con.getHeaderFieldKey(i); cj ?aCVa
if(header!=null) rG7E[kii
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;pk4Voo$
Utility.log(header+" : "+con.getHeaderField(header)); p,_,o3@~
else #-76E
break; vW`Dy8`06
} "B18|#v
} Leg)q7n
>uVo'S.
~s.~X5
public void splitterStop() l=EnK"aU
{ =T_E]>FF9
bStop = true; UQq,Xq
} YU=Q`y[k
>R9Q|
+tsF.Is!t
} U^qQ((ek
p mv6m
0,1x- yD
/* HEqTlnxUu
**FileAccess.java R8[l\Y>Ec
*//文件访问(定位，写) ?HD(EGdx
package NetFox; ,1xX`:
import java.io.*; Po(Y',xI[
9;W2zcN
ie<zc+*rW
public class FileAccessI implements Serializable{ L7kNQ/
qp#Is{=m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 36]pE<
RandomAccessFile oSavedFile; }~W:3A{7;
long nPos; w&c6iFMd0
xIt'o(jQH
Y-Iu&H+\
public FileAccessI() throws IOException !H)$_d \uj
{ |nOqy&B
this("",0); ;Dh\2! sr
} z@bq*':~J
++9?LH4S4
;_$Q~X
public FileAccessI(String sName,long nPos) throws IOException m1pge4*
{ )FLDCer
oSavedFile = new RandomAccessFile(sName,"rw"); PjwDth A1
this.nPos = nPos; r4YiXss
oSavedFile.seek(nPos); &Hz{
} dh9Qo4-{
VtP^fM^{
_v/w ,z
public synchronized int write(byte[] b,int nStart,int nLen) ;$a+ >
{ W4OL{p-\/
int n = -1; Uu_g_b:z
try{ 9Wu c1#
oSavedFile.write(b,nStart,nLen); pyHU+B
n = nLen; 3o_)x
} _\/KI /
catch(IOException e) n8pvzlj1
{ WdWMZh
e.printStackTrace (); |Do+=Gr$t@
} P}`|8b1W
PL/g@a^tY
&7\=Jw7w
return n; h.Y&_=Gc
} ddTsR
lF[m*}l
^`~s#L7
} $&25hvK,
rCK
%>p[;>jW
/* G_m$?0\
**SiteInfoBean.java ]!c59%f=
*/ r5RUgt
package NetFox; J#>)+
/b1+ ^|_
]iU8n (5f
public class SiteInfoBean { )])nd"E
}}Zwdpo
|?cL>]t
private String sSiteURL; //Site's URL =l)D$l
private String sFilePath; //Saved File's Path *&vlfH
private String sFileName; //Saved File's Name !1b}M/Wx
private int nSplitter; //Count of Splited Downloading File c;X%Ar
X!b+Dk
0dTHF})m
public SiteInfoBean() $#z-b@s=B
{//nSplitter的缺省值为5 {4n
//default value of nSplitter is 5 4,,@o
this("","","",5); 8t;vZ&
} _ez*dE%
@Ojbu@A
t!8(IR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +TZVx(Z&A
{ Af"p:;^z
sSiteURL= sURL; v~*Co}0OB
sFilePath = sPath; oW5Ov
sFileName = sName; 70GwTK.{~
this.nSplitter = nSpiltter; =.`:jZG
|Q(3rcOrV"
pqCp>BO?O
} xA'RO-a}h
[+F6C
dEhFuNO<2
public String getSSiteURL() 0$qK: ze
{ dfA2G<Uc
return sSiteURL; :@RX}rKG
} dO1h1yJJ
KqL+R$??"(
~W2Od2p!
public void setSSiteURL(String value) ?NVX# t'
{ [;C|WTYSL
sSiteURL = value; Zv0'OX~8i
} {'-^CoR
| |u
%ws@t"aER
public String getSFilePath() BvLC%
{ ^, &'
return sFilePath; /HE{8b7n3F
} N79?s)l:K
3Q#Tut
Ez/>3:;
public void setSFilePath(String value) d4m@u$^1B
{ dEI]|i r
sFilePath = value; hcqg94R#_
} cCx_tGR"
{.j030Q
J'E?Z0
public String getSFileName() cGSG}m@B`
{ :caXQ)
return sFileName; ri2`M\;gt
} +gyGA/5:d$
M9QYYo@
to{7B7t>q
public void setSFileName(String value) >g;995tG
{ +MtxS l
sFileName = value; nK)hv95i_
} 35H.ZXQp-
aH&Efz^
RhWW61!"
public int getNSplitter() gF2,Jm@"6
{ zEKVyZd*{
return nSplitter; m++=FsiX=
} Lng@'Yr
_]zH4o<p
l[6lXR&|
public void setNSplitter(int nCount) 0m,q3
{ `< 82"cAT{
nSplitter = nCount; hK UK#xx
} ?sW}<8\
} [VE>{4]W
d}2(G2z^
7lx]`u>
/* rhDiIO_
**Utility.java [;Jq=G8&t
*/ z?t75#u9.
package NetFox; 4iv&!hAc;
zGwM# -
oh7tE$"c
public class Utility { iOtf7.@
}OqP`B
xnDst9%
public Utility() 6@;sOiN+
{ HPXJRQBE
uE}$ZBiq
X>i{288M3
} cAn_:^
A[`2Mnj
//线程睡眠 !-m 'diE
public static void sleep(int nSecond) & h\!#X0
{ *mz-g7
try{ !E6QED"
Thread.sleep(nSecond); H@te!EE
} i!*8@:VI
catch(Exception e) b"nD5r
{ [ut[W9
e.printStackTrace (); txiX1o!/L
} Cwl:
} \[d~O>k2
t[/APm-k~>
//日志 D?G'1+RIT~
public static void log(String sMsg) -6xh
{ 8 q>
System.err.println(sMsg); (W.G&VSn)
} 4N5\sdi
/@1pm/>ZaN
Fd#Zu.Np
public static void log(int sMsg) VV/aec8
{ 4+Jf!ovS=
System.err.println(sMsg); 1/v#Z#3[
} V0G[f}tm'
} 3pe1"maP
Y(Y#H$w
]QQeUxi
/* FzAzAl5
**TestMethod.java ,Fn-SrB:
*/ ?aguAqG$
package NetFox; V}ls|B$Y
}tQ^ch;Q
/i{V21(%
public class TestMethod { C%|m[,Gx
}lP`3e
BZ(DP_}&D
public TestMethod() "y60YYn-#J
{ ///xx/weblogic60b2_win.exe ^I{/j'b&
try{ X%T%N;P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =y=MljEX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &(m01
SiteFileFetch fileFetch = new SiteFileFetch(bean); Hp*N%
fileFetch.start(); -@XOe&q
} AwZz}J+
catch(Exception e){e.printStackTrace ();} RIDl4c [
ZFX6iAxd
e>P>DmlW
} T!i$nI&
03.\!rZZ
$}fY B/
public static void main(String[] args) mNsd&Rk'
{ uDLj*U6L
new TestMethod(); TuC
} '>HLE)l
} L4ZB0PmN'
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