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)); epe}^Pl
} Q4 S8NqE
for(int i=0;i<nEndPos.length-1;i++) JE!Xf}nEi
{ ~<-h# B
nEndPos = nStartPos[i+1]; SJe;T
} 4\iQ%fb
nEndPos[nEndPos.length-1] = nFileLength; ;bmd<1
} Ml ^Tb#
} HRh".!lxy
o$;x[US
B 8,{jwB
//启动子线程 4,8 =[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j'cS_R
for(int i=0;i<nStartPos.length;i++) 1NJ|%+I
{ ~d]7 Cl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jeNEC&J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Er`PYE J
nStartPos,nEndPos,i); vN+!l3O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }2"k:-g
fileSplitterFetch.start(); nIT=/{oyi
} y+<HS]vyV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vh&KfYY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |M&/(0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [sRQd;+
nEndPos = " + nFileLength); 6IH^rSUSK
// fileSplitterFetch[nPos.length-1].start(); su$juI{
h[?28q$
+/'jX?7x%
//等待子线程结束 ,y @3'~
//int count = 0; S{06bLXU"
//是否结束while循环 73X]|fy
boolean breakWhile = false; 4B 6Aw?
^}#!?"Y
KYaf7qy]
while(!bStop) D=$<Ex^p
{ =nl,5^
write_nPos(); 1lM0pl6M
Utility.sleep(500); oB@C-(M
breakWhile = true; h !1c(UR
Bc@e;k@i
R _%pR_\
for(int i=0;i<nStartPos.length;i++) wH.'EC
{ 3& $E
if(!fileSplitterFetch.bDownOver) J(]nPwm=.-
{ "-oC,;yq
breakWhile = false; 6fiJ' j@
break; cE[lB08
} .nN7*))Fj
} ~%ZO8X:^
if(breakWhile) %K4-V5f
break; r`@Dgo}
IYFA>*Es
ub&1L_K
//count++; L $~Id
//if(count>4) `y(3:##p
// siteStop(); n1|%xQBU@
} kW9STN
Fu$otMw%l
A [JV*Dt
System.err.println("文件下载结束！"); qA42f83
} `:&{/|uP7
catch(Exception e){e.printStackTrace ();} YH9BJ
} KK}&4^q
(46)v'?
bPEAG=l"-
//获得文件长度 p#w,+)1!d
public long getFileSize() "x)W3C%*S
{ $A,=z
int nFileLength = -1; ZJqmD
try{ (~~=<0S
URL url = new URL(siteInfoBean.getSSiteURL()); //(c 1/s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >8##~ZuF+
httpConnection.setRequestProperty("User-Agent","NetFox"); v3B ^d}+.
iDA`pemmi&
\[BnAgsF
int responseCode=httpConnection.getResponseCode(); ?w+T_EH
if(responseCode>=400) Hs9uDGWp
{ RB!g,u
processErrorCode(responseCode); sQkP@Y
return -2; //-2 represent access is error !Kis,e
} DbDpdC;
S/4kfsN
!PgYn
String sHeader; f"Z2&Y@
k`d
Wd7*sa3T
for(int i=1;;i++) udB}`<Q
{ VC@o]t5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eP)RP6ON{
//Utility.log(in.readLine()); "](~VF[J8
sHeader=httpConnection.getHeaderFieldKey(i); XxGm,A+>Ty
if(sHeader!=null) bFpwq#PDW>
{ 9}=Fdt
if(sHeader.equals("Content-Length")) `fH6E8N
{ G8SJ<\?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p=zjJ~DVd
break; U*Q$:%72vO
} pd|s7
} 1~+w7Ar=(
else 5)vXmAD/0
break; l"+=z.l6;
} bvoR?D\-"
} xn-n{U"
catch(IOException e){e.printStackTrace ();} #pZ3xa3R
catch(Exception e){e.printStackTrace ();} !`u)&.t7
/N$T[
p(v.sP4w
Utility.log(nFileLength); QAR<.zXvP
(b(iL\B$D=
MKbW^:
return nFileLength; \oi=fu=}*
} \ZC7vM"h
b@7 ItzD
o,29C7Ii
//保存下载信息（文件指针位置） @'S-nn,sO
private void write_nPos() y,aASy!Q
{ A 9u9d\
try{ #pIb:/2a_
output = new DataOutputStream(new FileOutputStream(tmpFile)); Nz m 7E]
output.writeInt(nStartPos.length); Y!5-WXH
for(int i=0;i<nStartPos.length;i++) bNXT*HOZb3
{ n7S[ F3
// output.writeLong(nPos); 3V-pLs|
output.writeLong(fileSplitterFetch.nStartPos); $I_aHhKt
output.writeLong(fileSplitterFetch.nEndPos); 0j*8|{|
} +=||c\'
output.close(); g;-CAd5
} u~K4fP
catch(IOException e){e.printStackTrace ();} 7&X^y+bMe6
catch(Exception e){e.printStackTrace ();} 9N9;EY-U
} =KX:&GU
hgm`6TQ
C&Rv)j
//读取保存的下载信息（文件指针位置） N(D_*% 96
private void read_nPos() G,J$lTX
{ @Fo0uy\G
try{ o/Z?/alt4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y'(;!5w
int nCount = input.readInt(); K\uR=L7
nStartPos = new long[nCount]; FsD}Nk=m~
nEndPos = new long[nCount]; !4|7U\;
for(int i=0;i<nStartPos.length;i++) HH>]"mv
{ /@0wbA
nStartPos = input.readLong(); zgLm~
nEndPos = input.readLong(); P5[.2y_qM
} >]Y`-*vw&
input.close(); o0AREZ+I
} rt f}4.
catch(IOException e){e.printStackTrace ();} NbSwn}e_
catch(Exception e){e.printStackTrace ();} =x=#Etj|
} 'E6)6N
4B) prQ3
!.9NJ2'8
private void processErrorCode(int nErrorCode) 4re^j4L~o
{ 0%v p'v
System.err.println("Error Code : " + nErrorCode); &7;W=uF
} q K]Wk+
=E{1QA0
p 5P<3(
//停止文件下载 Z(Xu>ap
public void siteStop() 5=l Ava#
{ [&e}@!8O`
bStop = true; MwiT1sB~
for(int i=0;i<nStartPos.length;i++) #*5A]"k
fileSplitterFetch.splitterStop(); n:HF&j4C,
xmbkn}@A
Tc{r}y[)
} R`Q9|yF\
} |06G)r&
//负责部分文件的抓取 h T4fKc7P
**FileSplitterFetch.java u"nyx0<
*/ EyozhIV
package NetFox; i: 1V\q%
WG9x_X&XJ
zDC-PHFHQ
import java.io.*; 41$7P[M;
import java.net.*; [9X1;bO#f
mim]nRd2v
iB{O"l@w
public class FileSplitterFetch extends Thread { i,,UD
/,wG$b+
>wZ!1Jq
String sURL; //File URL CJ?Lv2Td
long nStartPos; //File Snippet Start Position ._#|h5
long nEndPos; //File Snippet End Position p^NYJV
int nThreadID; //Thread's ID *ZAue.
boolean bDownOver = false; //Downing is over #VtlXr>G
boolean bStop = false; //Stop identical ?NJ\l5'
FileAccessI fileAccessI = null; //File Access interface bq]af.o*
R:-^,/1
0Bb amU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AS~O*(po
{ H+t^eg88
this.sURL = sURL; "|(+~8[
this.nStartPos = nStart; BoXQBcG]w
this.nEndPos = nEnd; ur"ckuG!9
nThreadID = id; 5yuR[VU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 njX!Ez
} [26"?};"%
LC2t,!RRl&
YEQ}<\B\&
public void run() [ q22?kT
{ y1B3F5
while(nStartPos < nEndPos && !bStop) 8nW#Q<s
{ 1Sr@$+VGO
LsoP >vJG
uee2WGD
try{ \f05(ld
URL url = new URL(sURL); o=7 -&F.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kF`2%g+
httpConnection.setRequestProperty("User-Agent","NetFox"); gCW.;|2
String sProperty = "bytes="+nStartPos+"-"; Kb#py6
httpConnection.setRequestProperty("RANGE",sProperty); BNnGtVAbZ
Utility.log(sProperty); xbSix:R=Z
5e6f)[}
?=$a6o
InputStream input = httpConnection.getInputStream(); ,_D`0B6o
//logResponseHead(httpConnection); %TP0i#J
8N'[)Jw
5F18/:\n
byte[] b = new byte[1024]; YOqGFi~`
int nRead; P_ U[OM\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !SMIb(~[z
{ 4,`Yx s)%
nStartPos += fileAccessI.write(b,0,nRead); XnV*MWv
//if(nThreadID == 1) k7'_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "l"zbW WOH
} lo5,E(7~h
?Bno?\
D<$,v(-
Utility.log("Thread " + nThreadID + " is over!"); :dc>\kUIv
bDownOver = true; #"|</*%>
//nPos = fileAccessI.write (b,0,nRead); <}&n}|!
} IXDj;~GF
catch(Exception e){e.printStackTrace ();} P{h;2b{
} Mpzt9*7R
} }.>( [\q
@2nar<
g ]e^;
//打印回应的头信息 YKlYo~fGN9
public void logResponseHead(HttpURLConnection con) ]6bh#N;.
{ +mIO*UQi
for(int i=1;;i++) .Ks%ar
{ L'iENZI$
String header=con.getHeaderFieldKey(i); tURjIt,I
if(header!=null) j'R{llZW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kI<;rP1S|
Utility.log(header+" : "+con.getHeaderField(header)); n6Je5fE
else E_[|ZrIO&*
break; dkVF
} dDK4I3a
} W2?6f:
/zJDQ'k0
US[{ Q
public void splitterStop() 2~h! ouleY
{ fkbHfBp[(A
bStop = true; M_lQ^7/
} roSdcQTeT
3#<b!Yz
A)/8j2
} b{%p
.fY1?$*6c
[#hpWNez(>
/* NCR4n_
**FileAccess.java !W4A9Th
*//文件访问(定位，写) O9?t,1
package NetFox; A/ZZ[B-
import java.io.*; `K5Lp>=R
+GqK$B(x7
v'na{"
public class FileAccessI implements Serializable{ $a.fQ<,\X
k<(G)7'gm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HI&N&a9C
RandomAccessFile oSavedFile; xMsSZ{j%5
long nPos; (cAWT,
tUU`R{=(
8S/SXyS
public FileAccessI() throws IOException {BPNb{dBKr
{ ?&A)%6` ~
this("",0); w*#B_6bG
} }x!=F<Q!r
Se~<Vpo
Ck.LsL-
public FileAccessI(String sName,long nPos) throws IOException rHYSS0*3
{ G8AT] =
oSavedFile = new RandomAccessFile(sName,"rw"); paCC'*bv
this.nPos = nPos; Jy<hTd*q
oSavedFile.seek(nPos); oHh~!#u
} 11Sflj
wzX(]BG
[.:SV|AF#
public synchronized int write(byte[] b,int nStart,int nLen) XK#~w:/fB
{ h.T]J9;9
int n = -1; q9+`pj
try{ zNG]v?JAh
oSavedFile.write(b,nStart,nLen); ',+YWlW
n = nLen; st4z+$L
} @>:V?
catch(IOException e) 5\!t!FL_
{ n1!hfu7@s
e.printStackTrace (); v\lhbpk
} Hreu3N
Yx#?lA2gx
R%Xhdcn7
return n; ={~?O&Jh
} @}K|/
n0)0"S|y1
S:5vC{
} vtx3a^
)T0%<(J
\iL{q^Im
/* py|ORVN(Z
**SiteInfoBean.java z3Id8G&>
*/ =#=<%HPT
package NetFox; @kh:o\
&<dC3o!
WzinEo{f
public class SiteInfoBean { 1F|e/h%^
dlv1liSXL5
&,*G}6wa;&
private String sSiteURL; //Site's URL Q+<{2oVz
private String sFilePath; //Saved File's Path FT'2J
private String sFileName; //Saved File's Name Y9<N#h#
private int nSplitter; //Count of Splited Downloading File -ElK=q
{4]sJT
vD-m FC)
public SiteInfoBean() Kx4_`;>
{//nSplitter的缺省值为5 YzA6*2
//default value of nSplitter is 5 yV.E+~y
this("","","",5); #!.26RM:P
} wqnrN6$jf
eeMeV>
sOVbz2\yb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;15j\{r
{ TKH!,Ow9A
sSiteURL= sURL; %>io$o
sFilePath = sPath; npCiqO
sFileName = sName; ,vcg%~-
this.nSplitter = nSpiltter; Q$bi:EyJXc
1`& Yg(
JX)%iJq#
} wjzR 8g0bQ
Qr.SPNUFK
Uf,fd
public String getSSiteURL() OK]_.v}
{ rbt/b0ET
return sSiteURL; DYf3>xh>xb
} HpKF7oJ'N
ZbAg^2
qrr[QEFW
public void setSSiteURL(String value) {,X}Btnwp
{ wH0m^?a!3
sSiteURL = value; xfzGixA
} XM#xxf* Y
uN;]Fv@Z
Ss~yy0
public String getSFilePath() k>.n[`>$6|
{ $n#NUPzG+
return sFilePath; ^]zC~LfG
} ']&rPvkL
Cs2F/M'
dbsD\\,2%N
public void setSFilePath(String value) <|=^['vi
{ Y=5}u&\
sFilePath = value; WU+OS(
} k.n-JS
}lQ`ka
4\Q pS
public String getSFileName() ix+sT|>
{ 0ZAT;eaB
return sFileName; <=Z`]8
} U(6=;+q
I xk+y?
MszX9wl
public void setSFileName(String value) al1Nmc#
{ hk.vBbhs
sFileName = value; $8{v_2C){
} y[A%EMd
Q!ReA{
9Hm>@dBhM
public int getNSplitter() wa%;'M&
{ AuIg=-xR
return nSplitter; )`,Y^`F2
} =\FV_4)
/^\UB fE
WNO!6*+
public void setNSplitter(int nCount) SL$ bV2T
{ H"vkp~u]I
nSplitter = nCount; :vXlni7N[M
} cCBYM
} G$oi>zt3
kn9e7OO##
Yc3Rq4I'G
/* Wz+7CRpeP
**Utility.java x='T`*HD
*/ vrX@T?>
package NetFox; [X^Oxs
I-L:;~.
0nsjihw
public class Utility { iOrpr,@
`Kb"`}`_vm
] ^s,
public Utility() :cA%lKg
{ ,SG-{
TfnBPO
I6vy:5d
} U'p-Ko#
$mu*iW\{
//线程睡眠 !m:rtPD'
public static void sleep(int nSecond) U+ANSW/
{ .^!<cFkCE
try{ $I|6v
Thread.sleep(nSecond); r7Zx<c
} (RU\a]Ry
catch(Exception e) fP8iz `n
{ rv<_'yj
e.printStackTrace (); [Ol~}@gV
} ,GUOq!z
} C3:CuoE X
EWC{896,
//日志 uA;vW\fHr
public static void log(String sMsg) C8W4~~1S
{ 9D[Jn}E:
System.err.println(sMsg); /8Ru O
} 0BrAgv"3a_
%CIRN}
3%L@=q
public static void log(int sMsg) ><wYk)0E
{ O6"S=o&
System.err.println(sMsg); 6%a:^f]
} @8eQ|.q]Q
} )%wNVW 0C
2+=:pc^
%EEQ^lm
/* ZG$PW<73~
**TestMethod.java u:w
*/ LTw.w:"J
package NetFox; "I,=L;p
Xrr3KQaK&
f!Mx +ky
public class TestMethod { hl$X.O
]x5+v0
A-f,&TO
public TestMethod() 9A,ok[J
{ ///xx/weblogic60b2_win.exe F[)5A5+:Y
try{ b6UpE`\z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YhQ%S}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0s!';g Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); de_%#k1:L
fileFetch.start(); O)$Pvll
} tA8O(9OV
catch(Exception e){e.printStackTrace ();} Xe2Zf
)skz_a}]8
Xv<K>i>k
} ({0:1*lF@
*CCh\+S7m
VT [TE
public static void main(String[] args) -?p4"[
{ {Jc.49
new TestMethod(); Seh(G
} ]Ns)fr6
} xG WA5[YV
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