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)); ]S4TX
} {Tb(4or?=b
for(int i=0;i<nEndPos.length-1;i++) ,TPNsz|Q
{ s1.YH?A;
nEndPos = nStartPos[i+1]; `W,gYH7
} Tu2BQ4\[
nEndPos[nEndPos.length-1] = nFileLength; 2mN>7Tj:
} WW82=2rJ9
} 7t=e"|^
^Lr)STh
Y+75}]B
//启动子线程 DP**pf%j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YzJ\< tkp
for(int i=0;i<nStartPos.length;i++) _Bm/v^(
{ L"6qS3[=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :=WiT_M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RO"c+|Py
nStartPos,nEndPos,i); E:/G!1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :bFCnV`Q
fileSplitterFetch.start(); 3qU#Rg ;7
} q'~?azg:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H~UxVQLPp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Njsz=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Tn2nd
nEndPos = " + nFileLength); ?JO x9;`
// fileSplitterFetch[nPos.length-1].start(); :%cL(',Q
~`)`Ip
( P|Ph
//等待子线程结束 9,wd,,ta
//int count = 0; 1CK}XLdr
//是否结束while循环 F`KA^ZI
boolean breakWhile = false; ,DsqKXSU
rKEi1b
+>mbBu!7
while(!bStop) +ptVAg+
{ 3;(;'5|Z
write_nPos(); ?n<b:oO
Utility.sleep(500); I:l<t*
breakWhile = true; 2Pn
Z ?`
9SF2
for(int i=0;i<nStartPos.length;i++) l]D?S]{a
{ "\M16N
if(!fileSplitterFetch.bDownOver) b@j**O>[q)
{ 5>+>=)*
breakWhile = false; ZD\`~I|gp
break; COPH)Bdq.
} Y-\/Y*;cd
} &TYTeJ]
if(breakWhile) 5q?2?j/h
break; D#|+PG7
$/^DY&
~?i;~S
//count++; Si#I^aF`%
//if(count>4) KPO?eeT.WZ
// siteStop(); ZYDLl8
} a_Y*pOu
dU%Q=r8R
<?UbzT7X
System.err.println("文件下载结束！"); 1%~yb Q
} EUH&"8 L
catch(Exception e){e.printStackTrace ();} ^_W+
} DZo7T!
0gdFXh$!e
(XW\4msB)I
//获得文件长度 6d/;GyG
public long getFileSize() Gq%q x4
{ 3\_ae2GW
int nFileLength = -1; 70bI}/u
try{ dl_ h0
URL url = new URL(siteInfoBean.getSSiteURL()); {"|P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OI0#@_L&
httpConnection.setRequestProperty("User-Agent","NetFox"); 2z9\p%MX
_K"|}bM
KW.*LoO
int responseCode=httpConnection.getResponseCode(); =kvfe" N0e
if(responseCode>=400) HE GMwRJG
{ n,D~ whZx
processErrorCode(responseCode); y'\BpP
return -2; //-2 represent access is error G|eY$5!i
} rMRM*`Q2
^<X+t&!z
N~7xj?
String sHeader; !$&k@#v:
K=,nX7Z5
)p*I(y
for(int i=1;;i++) VN!`@Ci/
{ xCU^4DO3p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q =sEtH=
//Utility.log(in.readLine()); ":s1}A
sHeader=httpConnection.getHeaderFieldKey(i); al>^}:
if(sHeader!=null) RsV<4$
{ A9Cq(L_H
if(sHeader.equals("Content-Length")) rg Gm[SL*<
{ m(MPVY<X
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?sfas57&y
break; `o~dQb/k+
} Ia_I~ U$
} *Ju$A
else K.3)m]dCl
break; %:i; eUKR
} +M4X r*
} thG;~W
catch(IOException e){e.printStackTrace ();} &+V6mH9m@
catch(Exception e){e.printStackTrace ();} Z*&y8;vUQ
n0|oV(0FE
\Tf[% Kt x
Utility.log(nFileLength); ~)>O=nR
#oBMA
DUBEh@
return nFileLength; 1k-YeQNe
} VB 53n'
h'*>\eC6
c@H_f
//保存下载信息（文件指针位置） ;',hwo_LBf
private void write_nPos() {OFbU
{ cp D=9k!*K
try{ 0($@9k4!/
output = new DataOutputStream(new FileOutputStream(tmpFile)); \@G 7Kk*l
output.writeInt(nStartPos.length); X!=E1TL
for(int i=0;i<nStartPos.length;i++) )P&>Tc?;z
{ @JJ,$?
// output.writeLong(nPos); CjtBQ5
output.writeLong(fileSplitterFetch.nStartPos); <1")JDW
output.writeLong(fileSplitterFetch.nEndPos); },r30`)Q
} :cDhqBMNr`
output.close(); n~~0iU)
} /S4$qr cM
catch(IOException e){e.printStackTrace ();} j1/.3\
catch(Exception e){e.printStackTrace ();} 8MUY
} +um Ua
L~x PIu
pkWJb!
//读取保存的下载信息（文件指针位置） l!r2[T]I@7
private void read_nPos() b6KO_s:'g
{ SvR:tyF
try{ 3FWl_d~uD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sEBZ-qql
int nCount = input.readInt(); /u hA\m(
nStartPos = new long[nCount]; uu08q<B5b)
nEndPos = new long[nCount]; TL^af-
for(int i=0;i<nStartPos.length;i++) nR%ASUx:Y
{ 06hzCWm#
nStartPos = input.readLong(); S b0p?
nEndPos = input.readLong(); ,'=Tf=wq
} CM$q{;y
input.close(); 3&H#LGoV$
} LjZvWts?
catch(IOException e){e.printStackTrace ();} 4sU*UePr
catch(Exception e){e.printStackTrace ();} j?!BHNs
} ~Sq!P
:{#%_^}k
w8MQA!=l
private void processErrorCode(int nErrorCode) -TIrbYS`
{ $raxf80A
System.err.println("Error Code : " + nErrorCode); &x~&]
} 8GRp1'\Hi
jC<1bf$K
syuW>Z8s
//停止文件下载 )-2sk@y
public void siteStop() 9\2<#,R1q
{ <5Ft3sd
bStop = true; U[l7n3Y=
for(int i=0;i<nStartPos.length;i++) K7G|cZ/^
fileSplitterFetch.splitterStop(); >F@qFPN]
4 h}03 oG
W6N3u7mrb
} '.Ww*N
} aQ@9(j> F
//负责部分文件的抓取 !_zp'V]?
**FileSplitterFetch.java U)v['5%
*/ WCa>~dF>
package NetFox; /g|H?F0
}>)e~\Tdzb
_e2=BE`W)
import java.io.*; o+9b%I^1V
import java.net.*; %[1\d)
608}-J=3#
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public class FileSplitterFetch extends Thread { 96L-bBtyY
1|]IWX|
to}g4
String sURL; //File URL Dt1v`T~=?
long nStartPos; //File Snippet Start Position nC-=CMWWr
long nEndPos; //File Snippet End Position G~$.Af!9W
int nThreadID; //Thread's ID ejr9e@D^
boolean bDownOver = false; //Downing is over CV9o,rL
boolean bStop = false; //Stop identical bfjC:"!H
FileAccessI fileAccessI = null; //File Access interface 0F"W~OQ6
X#625h
7(ni_|$|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u%TZ),ny-
{ <F>^ffwGH-
this.sURL = sURL; bn$('
this.nStartPos = nStart; z%lu%
this.nEndPos = nEnd; 'hEvW
nThreadID = id; ]4{ )VXod
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O)0}yF$0
} @D?KS;#
c"nowbf
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public void run() |E%i t?3M
{ x,U'!F
while(nStartPos < nEndPos && !bStop) 0_!')+
{ (d> M/x?W
cRR[ci34k
^Y;}GeA,
try{ 7WEh'(`
URL url = new URL(sURL); %l4;-x<e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^M:Y$9r_s
httpConnection.setRequestProperty("User-Agent","NetFox"); 3q$[r_
String sProperty = "bytes="+nStartPos+"-"; &.m.ruab
httpConnection.setRequestProperty("RANGE",sProperty); fGeDygV^`
Utility.log(sProperty); y4@zi"G
>i6sJ)2?>
l**gM
InputStream input = httpConnection.getInputStream(); ?L%BD7
//logResponseHead(httpConnection); ^{Vt
d4#CZv[g/
:\!D 6\o6
byte[] b = new byte[1024]; Yk;-]qi7
int nRead; jOkc'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,A$#gLyk<
{ 3/aK#TjK
nStartPos += fileAccessI.write(b,0,nRead); 1*x;jO>Hk
//if(nThreadID == 1) )S:,q3gxJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eD(;Wn
} bv&#ay7
Rm&^[mv
Z[ NO`!<
Utility.log("Thread " + nThreadID + " is over!"); li @:
bDownOver = true; Qu x1N
//nPos = fileAccessI.write (b,0,nRead); m1 tYDZ"i
} <Ny DrO"C3
catch(Exception e){e.printStackTrace ();} +:IwP
} p\'0m0*
} 6UAn#d9
;+Dq3NE
|w{}h6a
//打印回应的头信息 2bs={p$}a
public void logResponseHead(HttpURLConnection con) 3jI rB%
{ >3C4S
for(int i=1;;i++) {h}0"5
{ z[cs/x
String header=con.getHeaderFieldKey(i); Jw4#u5$$Z
if(header!=null) ^vj}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s~z~9#G(6
Utility.log(header+" : "+con.getHeaderField(header)); }&*wJ]j`L
else & t.G4
break; r_x|2 AoO
} ~E8L,h~
} #`HY"-7m_
FI(iqSJ6
d3[O!4<T
public void splitterStop() >=6 j:
{ h7P<3m}
bStop = true; f-!P[6bY
} wv7XhY}
hZ[(Ik]*Zd
Ah?,9r=U
} ^t$xR_
@^2?97i c
O x),jc[/
/* =d*5TyAcu
**FileAccess.java t=;P1d?E;
*//文件访问(定位，写) 8ofKj:W]
package NetFox; rjo1
import java.io.*; N^TE ;BM
@Y&UP
H{BP7!t[V
public class FileAccessI implements Serializable{ D}MCVNd^
lEYAq'=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L25v7U
RandomAccessFile oSavedFile; {@&%Bq*&
long nPos; 2.2G79U,
\C}_l+nY
mm:g9j
public FileAccessI() throws IOException ;ztt*py
{ (M-Wea!q
this("",0); *}P=7TuS
} M%z$yU`ac
qRcY(mb
Q H57[Yg
public FileAccessI(String sName,long nPos) throws IOException JQ%D6b
{ 7C>5XyyJ
oSavedFile = new RandomAccessFile(sName,"rw"); L)z`
this.nPos = nPos; 1EemVZdY
oSavedFile.seek(nPos); _/5#A+ ?
} SjL&\),
?/1Eu47
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public synchronized int write(byte[] b,int nStart,int nLen) )j+G4
{ X-<l+WP
int n = -1; vveL|j
try{ nJhaI
oSavedFile.write(b,nStart,nLen); c9:8KMF)
n = nLen; ~QngCg-5q
} Fl}{"eCF8
catch(IOException e) VsQ~Y,7
{ Fz{T;
e.printStackTrace (); i}gsxq%
} KK';ho,W
#8/pYQ;
V^%P}RFMc
return n; }pJLK\
} asZ(Hz%
vACJE
\(&UDG$
} GWa:C\YK
?0x=ascP
G -V~6
/* va[r~
**SiteInfoBean.java 928uGo5
*/ l{mC|8X
package NetFox; EdTR]}8
mlO\wn-F
?`/DFI'_G
public class SiteInfoBean { WyU\,"
%PlA9@:IZ
IKVFbTX:y
private String sSiteURL; //Site's URL O^~Z-;FA
private String sFilePath; //Saved File's Path +`f3_Xd
private String sFileName; //Saved File's Name <lgX=wx L
private int nSplitter; //Count of Splited Downloading File vLs*}+f
c->.eL%
(b8ZADI*
public SiteInfoBean() :pdl2#5H^
{//nSplitter的缺省值为5 85_Qb2<'r
//default value of nSplitter is 5 (3?W)i
this("","","",5); n.7-$1
} -oT3`d3
[tk6Kx8a
M.9w_bW]#D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cBtQ2,<6
{ uI\6":/u
sSiteURL= sURL; WXQ+`OH7
sFilePath = sPath; %+iAL<S
sFileName = sName; 9UCA&n
this.nSplitter = nSpiltter; %W^Zob
?UV|m
b ;>?m
} Kz"&:&R"
Nj{;
9~{,Hj1xE
public String getSSiteURL() zG)vmysJf
{ aen0XiB6~^
return sSiteURL; lkW5<s_
} >o1,Y&
uvl>Z= "
2j&0U!DX
public void setSSiteURL(String value) 6xLQ
{ wpg7xx!
sSiteURL = value; Ot{~mMDp
} 5><T#0W?
f0{j/+F_o
_9y!,ST
public String getSFilePath() DMA`Jx
{ 7$mB.\|
return sFilePath; 6x;!E&<
} [P`<y#J3F
U%n>(!d
>U)>~SQf
public void setSFilePath(String value) P~;1adi3
{ "hnvND4=
sFilePath = value; /\MkH\zg
} 8?1MnjhX10
6^)eW+
{_4`0J`3
public String getSFileName() >en\:pJn)'
{ On0,#i=
return sFileName; / 5/mx
} [)?yH3
ft1V1 c
aVZ/e^kk-
public void setSFileName(String value) _p'u!.a?!
{ X>%li$9J.
sFileName = value; TZhYgV
} 48Jt1^
e>x+Xj1
J7HY(7Nx
public int getNSplitter() pV O{7I
{ Y+h ?HS
return nSplitter; f!F5d1N
} v]#[bqB.b
i>KgkRZL#
P#}vi$dZ
public void setNSplitter(int nCount) <}G/x*N
{ rv c%[HfW;
nSplitter = nCount; 1DlXsup&?#
} Z23T2
} [6Q1yNE
M)~sL1)
-O\fy!
/* b&6lu4D
**Utility.java R$`%<Y3)
*/ xDNXI01o
package NetFox; @hwNM#>`
<{j;']V;
OC)=KV@KE
public class Utility { JNo[<SZb
^<_rE-k
CjEzsjqe<I
public Utility() ' g d=\gV
{ UOyM=#ipY
J%lrXm(l{
51-'*Y
} }0sLeGJ!
5"ooam3
//线程睡眠 ..5.":
public static void sleep(int nSecond) RXw1HRR$V
{ b~2LD3"3
try{ 6z]y =J
Thread.sleep(nSecond); _sn<"B%>
} jO9!:L>b`
catch(Exception e) bokr,I3
{ _9dW+
e.printStackTrace (); NKc<nYdK?
} (*kKfg4Wj
} 9I*2xy|I
Ta$55K0
//日志 uw/N`u
public static void log(String sMsg) 4C )sjk?m
{ 3Kc9*]D
System.err.println(sMsg); U'u_'5{
} ~NB|BwAh
CM7NdK?I
]^8CtgC
public static void log(int sMsg) Bw~jqDZ}|
{ /N#=Tol
System.err.println(sMsg); x4h.WDT$
} Gqj(2.AY
} ^j@+!A_.Q
'u%vpvF
W.%p{wB|
/* 8llXpe
**TestMethod.java NwdrJw9
*/ X(BX+)YR
package NetFox; K4]#X"
x!7r7|iV
fg lN_
public class TestMethod { ox_DEg7l
l-Ha*>gX[j
l*{Bz5hc
public TestMethod() s}-j.jzB{
{ ///xx/weblogic60b2_win.exe / !y~Q|<|=
try{ fP6\Ur
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =M}tet }
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n^b CrvD
SiteFileFetch fileFetch = new SiteFileFetch(bean); \RtFF
fileFetch.start(); V(:wYk?ZR
} >?_}NZ,y
catch(Exception e){e.printStackTrace ();} y^[t3XA6Q
9_4(}|"N|
:pNS$g[
} .R#-u/6g(
V7`vLs-
sAPQbTSM
public static void main(String[] args) RNQq"c\
{ :I2,
new TestMethod(); ,F*HZBNFZ
} A,xPA
} 5%4yUd#b
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