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)); )JhB!P(
} R-tZC9 @
for(int i=0;i<nEndPos.length-1;i++) y1B'_s
{ S@Aw1i p
nEndPos = nStartPos[i+1]; Z|xgZG{
} kAs=5_?I
nEndPos[nEndPos.length-1] = nFileLength; ]IH1_?HgP7
} <vt}+uMzXv
} xy4P_
0xH&^Ia1B
Y8c,+D,Ww
//启动子线程 [8&+4<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y*sw;2Z;a
for(int i=0;i<nStartPos.length;i++) u7
{ :Sn4Pg `Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OVGB7CB]S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .:O($9^Ho
nStartPos,nEndPos,i); :r7!HG_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SPm2I(at7
fileSplitterFetch.start(); <j1r6.E)
} "JE->iD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %~[@5<p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pJIJ"o'>.9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o%*C7bU
nEndPos = " + nFileLength); 7CwWf
// fileSplitterFetch[nPos.length-1].start(); S R s
.\:MB7p
tAkv'.
//等待子线程结束 ^91Ae!)d
//int count = 0; na@Go@q
//是否结束while循环 DGg1TUE
boolean breakWhile = false; `6(Zc"/ \m
|Mgzb0_IiQ
HX ,\a`
while(!bStop) ZC`VuCg2O
{ iNilk!d6Q3
write_nPos(); `dhBLAt
Utility.sleep(500); hV&"
breakWhile = true; 6{I6'+K~
;U#=H9_
^oR qu
for(int i=0;i<nStartPos.length;i++) 4'td6F
{ Awr(}){
if(!fileSplitterFetch.bDownOver) @"H7Q1Hg!*
{ 7~);,#[ky
breakWhile = false; Eqi;m,)
break; pG22Nx
} JvNd'u)Z<
} 3p]\l ]=
if(breakWhile) /qFY$vj
break; E{}J-_oS45
*P|~vCnr
!?lvmq
//count++; J:OP*/@='
//if(count>4) 0sH~H[ap
// siteStop(); Wiw~oXo
} >!%+9@a}
6n~)R
WVz2 bzj
System.err.println("文件下载结束！"); N`4XlD
} _# cM vlk
catch(Exception e){e.printStackTrace ();} KD]`pqN9
} nm_4E8&X
^=8/Iw
0O>M/ *W
//获得文件长度 QEMT'Cs
public long getFileSize() *j=58d`n
{ ]wfY<Z
int nFileLength = -1; PPh<9$1\g
try{ =RZPDu
URL url = new URL(siteInfoBean.getSSiteURL()); ZXXJ!9-&+J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Inu'p\
httpConnection.setRequestProperty("User-Agent","NetFox"); ))<vCfuz2
S9^SW3
X_!km-{
int responseCode=httpConnection.getResponseCode(); h50]%tp\
if(responseCode>=400) %V#MUi1
{ <"}t\pT]
processErrorCode(responseCode); iP@FXJJ
return -2; //-2 represent access is error ,v`03?8l(
} E~VV19Bv]/
R~eLEjezm
PjXiYc&
String sHeader; OUFy=5(%:
G6lC[eK
Xk1uCVUe5
for(int i=1;;i++) #l@P}sHXq
{ "zkQu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YV} "#
//Utility.log(in.readLine()); r4<As`&
sHeader=httpConnection.getHeaderFieldKey(i); !b&+2y2i[W
if(sHeader!=null) ,*YmXR-"
{ 5z2("[8L&
if(sHeader.equals("Content-Length")) u,{R,hTDS
{ 4S4gK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pjQyN|KS
break; ><xmw=
} qz2`%8}F)
} n5;@}Rai
else <4<y
break; $G{j[iLY
} y%x:~.
} r;"D>IM\
catch(IOException e){e.printStackTrace ();} n-{d7haOa
catch(Exception e){e.printStackTrace ();} x+ER 3wDD@
;$e)r3r`LV
mSvSdKKKlI
Utility.log(nFileLength); &#KN"uPW
\)6bLB!
wLb:FB2
return nFileLength; 4jGN:*kZ
} dQ_4aO
_l1"X^Aa
g-B{K "z
//保存下载信息（文件指针位置） g^x=y
private void write_nPos() C`.eJF
{ G e5Yz.Qv
try{ l)~U8
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2`j{n\/
output.writeInt(nStartPos.length); E'98JZ5ga
for(int i=0;i<nStartPos.length;i++) (y~%6o6
{ :U=3*f.{
// output.writeLong(nPos); )WW*X6[k
output.writeLong(fileSplitterFetch.nStartPos); R eb.x_
output.writeLong(fileSplitterFetch.nEndPos); Q1ayd$W@<
} <mj/P|P@
output.close(); lpS v
} 6VuyKt
catch(IOException e){e.printStackTrace ();} ,>za|y<n
catch(Exception e){e.printStackTrace ();} }0Uh<v@
} /8nUecr
DVMdRfA
_0FMwC#DY
//读取保存的下载信息（文件指针位置） e6mm;@F>
private void read_nPos() D$>&K&
{ *wY+yoj
try{ #:P$a%V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nnvS.s`O
int nCount = input.readInt(); !]Qk?T~9-
nStartPos = new long[nCount]; B~|]gd
nEndPos = new long[nCount]; R9Wr?
for(int i=0;i<nStartPos.length;i++) J/:U,01
{ 'o4`GkNh)
nStartPos = input.readLong(); o0>|
nEndPos = input.readLong(); V6'u\Ch|
} /U0Hk>$~(
input.close(); |)" y
} ^suQ7#g
catch(IOException e){e.printStackTrace ();} "I:*
catch(Exception e){e.printStackTrace ();} RAk"C!&^m
} HV-;?5
I8% -ii
qY'+@^<U;
private void processErrorCode(int nErrorCode) Pk;yn;
{ 7U1M;@y
System.err.println("Error Code : " + nErrorCode); "Nb2[R
} Y .cjEeL@
6 C O5:\
Q4L=]qc T
//停止文件下载 QBH|pr
public void siteStop() -mGG:#yP
{ 0l& '`
bStop = true; 9<toDg_
for(int i=0;i<nStartPos.length;i++) <DPRQhNW]
fileSplitterFetch.splitterStop(); jkta]#O
F$jy~W_
bvrXz-j
} - 0q263z
} 2boyBz}=S
//负责部分文件的抓取 /;/:>c
**FileSplitterFetch.java 9N{?J"ido
*/ Y`{62J8oy
package NetFox; ,c$tKj5ulQ
1gcWw, /
6-tIe_5
import java.io.*; zPybPE8
import java.net.*; j~V$q/7S
l2YClK
@mv G=:k
public class FileSplitterFetch extends Thread { 1?^ P=^8
Ejr'Yzl3_
/kK!xe
String sURL; //File URL q~5zv4NX
long nStartPos; //File Snippet Start Position bZ:+q1 D
long nEndPos; //File Snippet End Position %4F\#" A
int nThreadID; //Thread's ID \`["IkSg7
boolean bDownOver = false; //Downing is over X>Q44FV!
boolean bStop = false; //Stop identical K(PSGlI f
FileAccessI fileAccessI = null; //File Access interface ]!P8{xmb@
S]|sKY
rc<Ix
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d4ld-y
{ 64mD%URT
this.sURL = sURL; G4P*U3&p
this.nStartPos = nStart; K1A<m=If
this.nEndPos = nEnd; tP*GYWI48
nThreadID = id; <2%9O;bV[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F[%k;aJ
} \P9ms?((A
=)c-Xz
_?cum~A@
public void run() )g^qgxnnV
{ ^BRqsVw9
while(nStartPos < nEndPos && !bStop) mDZA\P_
{ qm_m8
)*XWe|H_
?PTXgIC
try{ k'N``.
URL url = new URL(sURL); S ~h*U2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nK+ke)'Zv=
httpConnection.setRequestProperty("User-Agent","NetFox"); ,ayJgAD
String sProperty = "bytes="+nStartPos+"-"; 2gkN\w6zQ
httpConnection.setRequestProperty("RANGE",sProperty); !G[%; d
Utility.log(sProperty); \,X)!%6kZ
!9YCuHj!p
$ (xdF
InputStream input = httpConnection.getInputStream(); #qF1z}L(
//logResponseHead(httpConnection); =Hn--DEMg
/3^XJb$Sa
iymN|KdpaZ
byte[] b = new byte[1024]; :aaX Y:<
int nRead; |4 \2,M#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1 hFh F^
{ |ka/5o
nStartPos += fileAccessI.write(b,0,nRead); 1W\wIj.
//if(nThreadID == 1) ^VG].6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1P1h);*Z
} EmrkaV-?k
-P|claO0
W^xO/xu1/
Utility.log("Thread " + nThreadID + " is over!"); [xrsa!$
bDownOver = true; ^xNzppz`]C
//nPos = fileAccessI.write (b,0,nRead); 3h=kn@I
} 6)?u8K5%r
catch(Exception e){e.printStackTrace ();} Jq(;BJ90R
} 5Rs#{9YE
} N[\J#x!U
V>Z4gZp5sc
SpU|Q1Q/h
//打印回应的头信息 :Z2997@Y
public void logResponseHead(HttpURLConnection con) [a!AKkj
{ 6("bdx;!
for(int i=1;;i++) #|(>UM\
{ Z : xb8]y
String header=con.getHeaderFieldKey(i); G'}N?8s1
if(header!=null) dL'oKh,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :7"Q
Utility.log(header+" : "+con.getHeaderField(header)); ;zo|. YD
else Sa9VwVUE
break; MI(#~\Y~P
} *P7/ry^<F
} siCm)B
W!O/t^H>
%bF157X5An
public void splitterStop() ercXw7{
{ ,<#Rk'y$
bStop = true; ys`oHSf
} 3T0-RP*
fR@Cg sw
%CvVu)tc
} *w _o8!3-
f sh9-iY8e
lkJxb~S
/* ,K\7y2/
**FileAccess.java <7rj,O1=
*//文件访问(定位，写) ]ilLed
package NetFox; wf]?:'}
import java.io.*; ]4[%Sv6]G
i\/'w]
]*mUc`
public class FileAccessI implements Serializable{ p o)lN[v
EKF4]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K/N{F\
RandomAccessFile oSavedFile; =:w,wI.
long nPos; F_R\
&@CUxK
wn.6l `
public FileAccessI() throws IOException u*=^>LD
{ eCN:
this("",0); h~9P34m
} 9m2FH~
'5$@I{z
k]r4b`x`
public FileAccessI(String sName,long nPos) throws IOException C^4,L \E
{ 3fQ`}OcNr
oSavedFile = new RandomAccessFile(sName,"rw"); }cCIYt\RK
this.nPos = nPos; &Lt$~}*&6
oSavedFile.seek(nPos); |36%B7H
} d;gs1]E50
gU|:Y&lFZg
xcmg3:s
public synchronized int write(byte[] b,int nStart,int nLen) s6!&4=ZA
{ "~ $i#
int n = -1; ZpOME@9,
try{ LkzA_|8:D
oSavedFile.write(b,nStart,nLen); 8+gp"!E
n = nLen; rYdNn0mhk
} "xTVu57Z[
catch(IOException e) TS+jDs
{ o jxK8_kl
e.printStackTrace (); wH@S$WT
} Yu)GV7\2
JHm Pa
$},XRo&R
return n; }`QZV_
} KyVzf(^
BRY/[QRqZ
-o"b$[sf=Z
} WUz69o be
NnHaHX
aBaiXv/*
/* }F.k,2
**SiteInfoBean.java ^8,prxaok
*/ %au>D
package NetFox; O-UA2?N@j
y_n4Y[4g
svEe@Kt`
public class SiteInfoBean { Os>&:{D4!
(Ytr&gh;0
Et}%)M
private String sSiteURL; //Site's URL K{DmMi];I
private String sFilePath; //Saved File's Path EU:N9oT
private String sFileName; //Saved File's Name ub>:dNBN
private int nSplitter; //Count of Splited Downloading File Qu'#~#L`
H#YI7l2
/"A=Yf
public SiteInfoBean() ai?J
{//nSplitter的缺省值为5 2Ul8<${c{
//default value of nSplitter is 5 b~tu;:
this("","","",5); qfCZ [D
} __tA(uA
0Mn|Yb4p
r7_%t_O|IL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $X Uck[
{ V1d#7rP
sSiteURL= sURL; ?b(wZ-/
sFilePath = sPath; PbvA~gm
sFileName = sName; fOSk> gK
this.nSplitter = nSpiltter; ]C"?xy
9"S iHp\)
e&i`/m5
} %$o[,13=
= )3\B
#U%HGTE0
public String getSSiteURL() .kuNn-$
{ ALF21e*n
return sSiteURL; '#=n>
} EMr|#}]#s
1@'I eywg
{#?|&n<
public void setSSiteURL(String value) +(:Qf+:
{ (:E@kpK
sSiteURL = value; S`b!sT-sD
} [6g$;SicT
4Lk<5Ho
Dl0{pGK~
public String getSFilePath() Z~94<*LEp
{ ,jz~Np_2
return sFilePath; =?y0fLTc
} l}(HE+?
;(}~m&p
lAo~w
public void setSFilePath(String value) 7O|`\&RYR
{ W-r^ME
sFilePath = value; ^4]=D nd%
} V+lS\E.
Z5U\>7@&8
G^h:#T
public String getSFileName() g^|R;s{
{ v8C($<3%
return sFileName; /=za m3kd
} K0vS
YhRy C*b
[ t8]'RI%
public void setSFileName(String value) J{a9pr6
{ Q{=r9&&
sFileName = value; 38X{>*
} =w!9:I&a0
SnUR?k1
eF7I5k4
public int getNSplitter() 7y30TU
{ 5/U{b5
return nSplitter; [8Z#HjhQ
} ;m.6 ~A
eTgtt-;VR
Ug0c0z!b
public void setNSplitter(int nCount) ,{(XT7hr
{ {*8G<&
nSplitter = nCount; =6\^F i
} rZB='(?
} x.pg3mVd>
J1gnR
$A,YQH+
/* WZ!zUUp}V
**Utility.java ^a /q6{
*/ vA6onYjA
package NetFox; ()Wu_Q
[P~7kNFOh
UB>BVBCt
public class Utility { 0x*|X@6\
o>+mw|{
FY)]yz
public Utility() g<^A(zM
{ JP( tf+
;C1#[U1Uy
T)q Uf H
} mb3aUFxA;
2PeMt^
//线程睡眠 !^NZp%Yd
public static void sleep(int nSecond) Hiwij,1
{ oz]3 Tx
try{ v/~&n
Thread.sleep(nSecond); 8[AU`F8W
} An?#B4:
catch(Exception e) 2Rwd\e.z
{ `) ],FE*:
e.printStackTrace (); 2(\PsN w!
} 6M_ W(
} q6sb;?I
y}={S,z%22
//日志 ZO<\rX (
public static void log(String sMsg) OA}; pQ9QN
{ Ke:EL;*8k
System.err.println(sMsg); qvWi;
} eYkg4O'
Pq{p\Qkj
S{MB$JA
public static void log(int sMsg) U%BtBPL
{ E|RC|Sz=u
System.err.println(sMsg); "+&pd!\
} (igB'S5wf
} >fT%CGLC0
X6t9*|C
e_!Z-#\J%
/* hHDLrr
**TestMethod.java M5:*aCN6P
*/ jVoD9H F/
package NetFox; iY,oaC~?"N
qZV|}M>P)
g;[t1~oF
public class TestMethod { ofz?L#:2
Q*'OY~
0/!0W%f[}
public TestMethod() +mR^I$9
{ ///xx/weblogic60b2_win.exe !z2xm3s{]p
try{ .tHc*Eh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {w"Cr0F,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }$uwAevP{y
SiteFileFetch fileFetch = new SiteFileFetch(bean); `0_ Y| 4KB
fileFetch.start(); >mMfZvxl%
} }C/+zF6q
catch(Exception e){e.printStackTrace ();} h|Qb:zEP,
O<@L~S]
,(sE|B#s
} `]4(Z"R
cZoj|=3a
*M#L)c;6
public static void main(String[] args) 6;!)^b
{ #s>'IPc0
new TestMethod(); jRDvVV/-wr
} %{^|Av1Uz
} R/E6n &R
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