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)); hqeknTGsIn
} F3V:B.C
for(int i=0;i<nEndPos.length-1;i++) $m ;p@#n
{ kKRu]0J~[
nEndPos = nStartPos[i+1]; 0#GnmH
} KLj/,ehD !
nEndPos[nEndPos.length-1] = nFileLength; q|lP?-j
} {)Zz4
} 5M>SrZH
PJKxh%J
*|+$7j
//启动子线程 k9y/.Mu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O"[#g
for(int i=0;i<nStartPos.length;i++) DM,;W`|6%
{ je:J`4k$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /HSg)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |f}`uF
nStartPos,nEndPos,i); 93.L887
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1JGww]JZo
fileSplitterFetch.start(); F9IPA%
} ;$r!eFY;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s BuXwa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .?F`H[^)^u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Yk7^?W
nEndPos = " + nFileLength); >u`Ci>tY
// fileSplitterFetch[nPos.length-1].start(); m}m|(;T
%CrpUx
Pi[(xD8
//等待子线程结束 DY87NS*HF
//int count = 0; ]V"B`ip[2
//是否结束while循环 0w$1Yx~C
boolean breakWhile = false; yAJrdY"
)B^T7{
;4vx+>-
while(!bStop) ZN;fDv
{ y|#Fu
write_nPos(); W$R@Klz
Utility.sleep(500); P9#}aw+
breakWhile = true; y(r(q
|uA /72
l'\m'Ioh
for(int i=0;i<nStartPos.length;i++) qS[nf>"
{ M`G#cEc
if(!fileSplitterFetch.bDownOver) e({-.ra
{ sGJZG
breakWhile = false; z0tm3ovp
break; 5bprhq-7
} <(o) * Zmo
} (Mt-2+"+
if(breakWhile) l9$"zEC
break; Z uO 7N
safI`bw1
^{+_PWn
//count++; O ;B[ZMV
//if(count>4) 5q.)K f+
// siteStop(); A!`Q[%$
} p w`YMk
<a%RKjQvT
ygTc Y
System.err.println("文件下载结束！"); $[*<e~?
} oei2$uu
catch(Exception e){e.printStackTrace ();} 6t`cY
} .|3&lb6
'WJ3q|o/
j|ZhGerp
//获得文件长度 #uH%J<U
public long getFileSize() 5*Y(%I<
{ $2pkh%
int nFileLength = -1; =E-V-?N\
try{ .0'FW!;FV
URL url = new URL(siteInfoBean.getSSiteURL()); 5'[b:YC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N>xdX5
httpConnection.setRequestProperty("User-Agent","NetFox"); Yhte&,D"
h?'~/@
@L$!hTaP
int responseCode=httpConnection.getResponseCode(); Q@KCODi
if(responseCode>=400) ( 4(,"
{ /]oQqZHv
processErrorCode(responseCode); 1]69S(
return -2; //-2 represent access is error VYjt/\Z
} {B-*w%}HU
lHAWZyO
8W Etm}
String sHeader; `I.pwst8i-
Vh{(*p
<*(^QOM
for(int i=1;;i++) $[UUf}7L
{ O,JS*jXl
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _\na9T~g
//Utility.log(in.readLine()); ;5DDV6
sHeader=httpConnection.getHeaderFieldKey(i); :V1j*)
if(sHeader!=null) 1mD)G55Ep
{ z]7/Gc,j
if(sHeader.equals("Content-Length")) [5!dO\-[
{ k%BU&%?1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j#0JD!Vr
break; @VPmr}p:{
} XO+rg&Pu
} >n^780S|
else C;j&Vbf
break; &r\8VEZq"
} M*f]d`B
} Evd|_W-
catch(IOException e){e.printStackTrace ();} -n8d#Qm)
catch(Exception e){e.printStackTrace ();} A,BYi$
`BVmuUMm
^=5x1<a9$
Utility.log(nFileLength); <z\`Ma
tj$[szo
g(Q1d-L4e
return nFileLength; _OC@J*4.
} Z"RgqNf
U(#JC(E-#
1X&.po
//保存下载信息（文件指针位置） > K?OsvX
private void write_nPos() 1[T7;i$
{ H>A6VDu
try{ 4M|uT 9-
output = new DataOutputStream(new FileOutputStream(tmpFile)); P:t .Nr"
output.writeInt(nStartPos.length); A&bj l[s
for(int i=0;i<nStartPos.length;i++) 9 @xl{S-
{ ddyX+.LMk
// output.writeLong(nPos); e"52'zAV-
output.writeLong(fileSplitterFetch.nStartPos); &iVdqr1,
output.writeLong(fileSplitterFetch.nEndPos); fjVy;qJ32S
} L-!1ybB^
output.close(); 8'HS$J;C
} B+snHabS6
catch(IOException e){e.printStackTrace ();} msM1K1er
catch(Exception e){e.printStackTrace ();} tw>2<zmSi%
} dWPQp*f2
,_fz)@)
hg(<>_~
//读取保存的下载信息（文件指针位置） m^G(qoZ]
private void read_nPos() #5Z`Q^
{ =y4dR#R(\
try{ !6T"J!F#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0n}13u=}
int nCount = input.readInt(); r~lZ8$KC
nStartPos = new long[nCount]; `(sb
nEndPos = new long[nCount]; w_xca(
for(int i=0;i<nStartPos.length;i++) 12KC4,C&1i
{ `;E/\eG"
nStartPos = input.readLong(); LmePJ
nEndPos = input.readLong(); |zYOCDFf
} 6t6Z&0$h~
input.close(); 6(Pan%
} _!R$a-
catch(IOException e){e.printStackTrace ();} x8PT+KC
catch(Exception e){e.printStackTrace ();} 6!ve6ZB[p
} yZ|"qP1
^Tm`motzh
2gPqB*H
private void processErrorCode(int nErrorCode) (~=.[Y
{ (Q^sK\
System.err.println("Error Code : " + nErrorCode); l%0bF9\
} rp||#v0l!w
hj [77EEz
d,V#5l-6
//停止文件下载 :$MOdL[ir
public void siteStop() Y$ys4X
{ &X$T "Dp
bStop = true; ~#A}=,4>
for(int i=0;i<nStartPos.length;i++) Z<-_Y]4j
fileSplitterFetch.splitterStop(); Nr~$i%[
$J`O-"M
r9i?H
} Wwq:\C
} `Y#At3{
//负责部分文件的抓取 = xO03|T;6
**FileSplitterFetch.java <Xf6?nyZ(
*/ !8{VLg
package NetFox; zj 6I:Qr
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v88vr
import java.io.*; ]a $6QS
import java.net.*; vygzL U^
2qMiX|Y
asWk]jjMG
public class FileSplitterFetch extends Thread { DUp`zW;B
[FFr}\}bY
L2}\Ah"[
String sURL; //File URL 'Wlbh:=$
long nStartPos; //File Snippet Start Position i8iT}^
long nEndPos; //File Snippet End Position A*JOp8\)
int nThreadID; //Thread's ID f|[7LIdh-
boolean bDownOver = false; //Downing is over l;?:}\sI=
boolean bStop = false; //Stop identical qu=~\t1[6
FileAccessI fileAccessI = null; //File Access interface TdhfX{nk
f:o.[4p2
|9*Rnm_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -y`Pm8
{ jqUVERbc
this.sURL = sURL; Z@~gN5@,M
this.nStartPos = nStart; r,5e/X
this.nEndPos = nEnd; &l(T},-X
nThreadID = id; ak(s@@k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <=(K'eqC^
} 7e_4sxg'(3
#S>N}<>
|J$A%27
public void run() u[a-9^&g
{ {^]qaQ[5N
while(nStartPos < nEndPos && !bStop) D T5d]MU
{ \!ZA#7
"~r<ZG
1+%UZK= K
try{ z#{Y>.b
URL url = new URL(sURL); X5WA-s(?0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hav&vV
httpConnection.setRequestProperty("User-Agent","NetFox"); j{C~wy!J
String sProperty = "bytes="+nStartPos+"-"; $tlBI:ay1
httpConnection.setRequestProperty("RANGE",sProperty); l)r\SE1
Utility.log(sProperty); h#1:ypA6l
}Qo]~/
0\mf1{$"!7
InputStream input = httpConnection.getInputStream(); ys=2!P-[#
//logResponseHead(httpConnection); Q%CrB>|@
HT7,B(.}
'o='Q)Dk
byte[] b = new byte[1024]; a1,)1y~
int nRead; Tzd#!Lvm:,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :tWkK$
{ \Z.r Pq
nStartPos += fileAccessI.write(b,0,nRead); 2Z; !N37U
//if(nThreadID == 1) >s<Bu'r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wvb ~j
} ,e'r 0
uc9h}QJ*
D;sG9Hky
Utility.log("Thread " + nThreadID + " is over!"); &Wy>t8DIK
bDownOver = true; lhM5a \
//nPos = fileAccessI.write (b,0,nRead); +S+!:IB
} $YJ 1P
catch(Exception e){e.printStackTrace ();} 8P]nO+
} Sr+hB>{
} p,=IL_
G 1{m"1M
hUpour |b
//打印回应的头信息 q:_:E*o
public void logResponseHead(HttpURLConnection con) e;v7!X
{ u.E>d9
for(int i=1;;i++) ?CCQm
{ drpx"d[c
String header=con.getHeaderFieldKey(i); 5$ How!
if(header!=null) ts=D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V 2Xv)
Utility.log(header+" : "+con.getHeaderField(header)); Zzlt^#KLx
else ,b^Y8_ltoT
break; mN-O{k0\
} lP=,|xFra
} uj;iE 9
6Takx%U
aP(~l_
public void splitterStop() }<kl3{)
{ Wrbv<8}%c
bStop = true; pPxgjX
} $Ptl&0MN%
DK2Wjr;
q'fOlq
} C!_=L?QT^
ipG 0ie+
ZYB5s~;eB"
/* J_a2DM6d
**FileAccess.java ZYY`f/qi
*//文件访问(定位，写) .WeSU0XG
package NetFox; 6x5Q*^w
import java.io.*; 3]iw3M
{%6 '|<`[
C-_u`|jQ
public class FileAccessI implements Serializable{ ,nog6\
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1A93ol=
RandomAccessFile oSavedFile; 2./z6jXW_
long nPos; DZ`,QWuA
dM,{:eID
'?90e4x3/
public FileAccessI() throws IOException ^-Ks_4
{ 8xj_)=(sV!
this("",0); &]f8Xd
} zWN]#W`
P;7[5HFF
* W"Pv,:
public FileAccessI(String sName,long nPos) throws IOException g}?39?o4
{ sj+ )
oSavedFile = new RandomAccessFile(sName,"rw"); F)l1%FCm
this.nPos = nPos; <,*w$
oSavedFile.seek(nPos); ?!tO'}?
} %YuFw|wO
EnMc9FN(y
G=Xas"|
public synchronized int write(byte[] b,int nStart,int nLen) t|&hXh{
{ D1]?f`
int n = -1; I_c?Ky8J_|
try{ aTaL|&(
oSavedFile.write(b,nStart,nLen); QVb{+`.7
n = nLen; x {Rj2~KC
} bHDZ=Ik
catch(IOException e) ASS<XNP
{ +>tSO!}[
e.printStackTrace (); YEiw!
} .L)j ql%
vA?3kfL|#
q)"yP\
return n; Fe2iG-ec
} `j6O
tB0f+ wC
o3'Za'N.
} ypvz&SzIh
|i(@1 l
Z%{`j!!p
/* `:gXQmt
**SiteInfoBean.java fo;^Jg.
*/ /7R0w
package NetFox; OV^?cA
(]"`>,ray
-+Ox/>k
public class SiteInfoBean { 7MX5hZF"
xy^z_`
]%(X}]}
private String sSiteURL; //Site's URL opReAU'I
private String sFilePath; //Saved File's Path `! )^g/>0i
private String sFileName; //Saved File's Name .|LY /q\A
private int nSplitter; //Count of Splited Downloading File ;C5 J^xHI
a;G>56iw
Zx|VOl,;
public SiteInfoBean() Ye\&_w"
{//nSplitter的缺省值为5 _WBWFGj
//default value of nSplitter is 5 U;]h/3P
this("","","",5); %hA0
} <xD6}h/
E(an5x/r
$*+`;PG-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sWMY Lo
{ j'LO'&sQ(
sSiteURL= sURL; NvJ}|w,Z
sFilePath = sPath; 'Fa~l'G7X
sFileName = sName; bx3kd+J7
this.nSplitter = nSpiltter; bSk)GZyH\d
l\&Tw[O
Vdb X4^V
} ;TCT%j`^o
CQET
cG4$)q;q
public String getSSiteURL() 6z1>(Za7>
{ 9:CM#N~?o
return sSiteURL; l\t<_p/I)^
} PLQLGb4f_;
DZU} p
-h#9sl->
public void setSSiteURL(String value) V?-OI>
{ F)uS2
sSiteURL = value; ),U>AiF]
} kSU]~x
"S0WFP\P+
? VHOh9|AT
public String getSFilePath() 52z{
{ q,2 +\i
return sFilePath; yxL(mt8
} +{H0$4y
"']|o~B
7G &I]>
public void setSFilePath(String value) 629#t`W\
{ 0I"r*;9?K
sFilePath = value; pcO0xrI
} L [=JHW
<P1x3
"DU1k6XC
public String getSFileName() &bT \4
{ 3YJa3fflK
return sFileName; @1O.;
} "/qm,$
GilmJ2<
Ig"QwvR
public void setSFileName(String value) p2uZ*sY(D
{ [W*Q~Wvp
sFileName = value; KBy*QA
} zpBkP-%}E
$ {5|{`
OCN@P+L3q
public int getNSplitter() 'MY0v_
{ [7@9wa1v!
return nSplitter; GR>kxYM%q
} We?cRb
t p<wMrq<
\O(~:KN
public void setNSplitter(int nCount) iFkXt<_A
{ s\3OqJo%)
nSplitter = nCount; ]@9ZUtU,;N
} ]c~W$h+F
} [ T!0ka
I*hzlE
~3,k8C"pRq
/* (~OP)F).
**Utility.java II) K0<
*/ 8m"jd+
package NetFox; caXSt2|'
X&s"}Hf
Ic')L*i7O
public class Utility { \_8.\o"@*#
^&Wa? m.
O"V;otlC
public Utility() 1Zt>andBF
{ s5 ($b
^g N/5
ViYfK7Z
} Ze"m;T
4I!g?Moh
//线程睡眠 w:c9Z=KX
public static void sleep(int nSecond) (L'|n*Cr
{ nR`)kORc
try{ br%l>Y\"
Thread.sleep(nSecond); t+Au6/Dx?
} Q.} guI\
catch(Exception e) ><i: P*ht
{ P^[y~I#{
e.printStackTrace (); J^y?nE(j
} /X;/}fk
} -OXC;y
=:BTv[lv
//日志 %WlTx&jSgE
public static void log(String sMsg) YDYN#Ob(;
{ DPr~DO`b
System.err.println(sMsg); $Ts;o
} bCqTubbx!t
t W}"PKv
z)Lw\H^/
public static void log(int sMsg) 2{<o1x,Ym
{ .t7ME{
System.err.println(sMsg); 3 #"!Hg
} -G(#,rXk
} V{UY_ e8W
:!ablO~
'<{Jlz(u9
/* xVk5%
**TestMethod.java 72ZoN<c
*/ Q^bYx (r5w
package NetFox; |k^C-
CaC \\5wl
{2k]$|
public class TestMethod { ^.9DfA0
%{-r'Yi%
+;-ZU
public TestMethod() vXm'ARj
{ ///xx/weblogic60b2_win.exe u\;d^A
try{ q%LjOPE V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C1>zwU_zo
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @C%6Wo4l3
SiteFileFetch fileFetch = new SiteFileFetch(bean); fN/;BT
fileFetch.start(); g(9kc<`3'D
} `hdN 6PgK
catch(Exception e){e.printStackTrace ();} />N#PF
..zX
z'*"iaX<c
} D5!#c-Y-
'E&tEbY
xS>vmnW
public static void main(String[] args) IEfYg(c0U
{ N\];{pe>
new TestMethod(); Zl>dBc%
} /EG'I{oC
} "7'P Lo3O
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