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)); >%tG[jb
} =Dq&lm,n
for(int i=0;i<nEndPos.length-1;i++) tDRR3=9pX
{ a$=~1@
nEndPos = nStartPos[i+1]; $Lp [i <O]
} &[[r|
nEndPos[nEndPos.length-1] = nFileLength; 8* A%k1+
} MDlH[PJ@i
} c& ;@i$X(
Yj@Sy
i47LX;}
//启动子线程 iN&oSpQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {32m&a
for(int i=0;i<nStartPos.length;i++) Wq4<9D
{ *6?mZ*GYY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "J"=<_?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?h[HC"V/2
nStartPos,nEndPos,i); b$b;^nly
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LFax$CZc
fileSplitterFetch.start(); UQu6JkbLL
} 86=W}eV1r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $9X+dvu*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OInl?_,,T#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tu}!:5xi
nEndPos = " + nFileLength); B@(d5i{h
// fileSplitterFetch[nPos.length-1].start(); I;w!
?b+Y])SJK
GURiW42
//等待子线程结束 {IgH0+z
//int count = 0; [h'u@%N|/
//是否结束while循环 v Z9OJrF
boolean breakWhile = false; p3Ux%/ZqPV
tpGT~Y(
;O}%SCF7
while(!bStop) Z{B e
{ BaQyn 6B
write_nPos(); M#gxiN
Utility.sleep(500); [\W&
breakWhile = true; %'1iT!g8
0''p29
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for(int i=0;i<nStartPos.length;i++) ui>jJ(
{ $bG*f*w
if(!fileSplitterFetch.bDownOver) &b|RoPV
{ ><}nZ7
breakWhile = false; Z9DfwWI2nu
break; +ALrHFG
} `TPIc
} Oz6$u
if(breakWhile) zu1"`K3b
break; !CU-5bpu
]`)5 Qe4
_-C/sp^
//count++; )Dz]Pv]H'
//if(count>4) M)#9Q=<
// siteStop(); fM ID}S
} EsKgS\`RZ
sm`c9[E
i6WPf:#wr
System.err.println("文件下载结束！"); {N}az"T4f
} ?xqS#^Z
catch(Exception e){e.printStackTrace ();} zwV!6xG
} JPZp*5c6A
%e]G]B%
th73eC'
//获得文件长度 nod&^%O"
public long getFileSize() 2H%lN`
{ LL e*|:
int nFileLength = -1; cjL)M=pIS
try{ c[ZrQJ
URL url = new URL(siteInfoBean.getSSiteURL()); _\4#I(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :6(\:
httpConnection.setRequestProperty("User-Agent","NetFox"); %/uLyCUZ
O5r8Ghf)
J>v[5FX+
int responseCode=httpConnection.getResponseCode(); lW?}Ts~'
if(responseCode>=400) =p4n@C
{ gbzBweWF
processErrorCode(responseCode); D=^&?@k<
return -2; //-2 represent access is error yo[Sh6r/9b
} S%MDQTM
?7NSp2aq2A
ULt5Zi
String sHeader; ,;t:x|{%
F2 B(PGa7
i6HRG\9nU
for(int i=1;;i++) :j`f%Vg~x
{ 3*I\#Z4p1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;J|t-$Z
//Utility.log(in.readLine()); z" tz-~
sHeader=httpConnection.getHeaderFieldKey(i); >fYcr#i0[
if(sHeader!=null) {Lal5E4-
{ DyqqY$ vH(
if(sHeader.equals("Content-Length")) )f$4:Pq
{ ;-`NT` #2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KyrZ&E.`
break; we_CF*zj
} AM=,:k$
} :jv(-RTI
else E@C.}37R
break; [lML^CYQ
} 9~`#aQG T
} a!bW^?PcK
catch(IOException e){e.printStackTrace ();} iN8[^,2H|
catch(Exception e){e.printStackTrace ();} d_we?DZ|
I;rW!Hb
iT&4;W=72~
Utility.log(nFileLength); 60|PVsmDm
+-qk\sQ
|kh{EUE ;
return nFileLength; wL~AL
} =iB[sLEJ
FiMM-c|
T(u;<}e@[
//保存下载信息（文件指针位置） lZRO"[<
private void write_nPos() 3ux7^au
{ lha;|
try{ eV!(a8
output = new DataOutputStream(new FileOutputStream(tmpFile)); w-JWMgY8w
output.writeInt(nStartPos.length); CN(-Jd.b
for(int i=0;i<nStartPos.length;i++) }&+,y<>
{ wtSU43D
// output.writeLong(nPos); W#!AZ!
output.writeLong(fileSplitterFetch.nStartPos); iPl,KjGk
output.writeLong(fileSplitterFetch.nEndPos); \dU.#^ryp
} MJX4;nbl
output.close(); %J-:%i
} &Ih}"
catch(IOException e){e.printStackTrace ();} jY\z+lW6A
catch(Exception e){e.printStackTrace ();} :%9R&p:'ar
} ch%zu%;f
ShL!7y*rT{
vfn[&WN]
//读取保存的下载信息（文件指针位置） hN K wQ
private void read_nPos() ?@PSD\
{ s@$0!8sxm
try{ |BM#rfQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h8O\sKn
int nCount = input.readInt(); 9h+Hd&=
nStartPos = new long[nCount]; p,k1*|j
nEndPos = new long[nCount]; !GvT{
for(int i=0;i<nStartPos.length;i++) nygGI_[l
{ UTE6U6
nStartPos = input.readLong(); zd2_k 9
nEndPos = input.readLong(); XM5)|D
} e.L&A|
input.close(); ;]xc}4@=mg
} pHb,*C</
catch(IOException e){e.printStackTrace ();} ShVR{gIs
catch(Exception e){e.printStackTrace ();} n;. M5}O
} zmZU"eWp)
%CnVK1u!
HOu$14g
private void processErrorCode(int nErrorCode) >QJDO ]~V
{ du}HTrsC
System.err.println("Error Code : " + nErrorCode); ~M* UMF^
} h{o,*QL
G6{PrV#
@i'D)6sC
//停止文件下载 IAkQR0fcN
public void siteStop() ?uc]Wgw"s
{ d~_5Jx
bStop = true; .<%q9Jy#
for(int i=0;i<nStartPos.length;i++) &S*{a
fileSplitterFetch.splitterStop(); `K0.6i [p
X&aQR[X
GGwwdB\x'
} ~}p k^FA
} !7~4`D c6U
//负责部分文件的抓取 rZ.=Lq
**FileSplitterFetch.java A #SO}c
*/ 27[e0 j
package NetFox; ]3|h6KWq
/QL<>g
?$;&DoE
import java.io.*; V6ECL6n
import java.net.*; &<#1G u_
RF6]_-
@|<nDd{2
public class FileSplitterFetch extends Thread { \Qv:7;?
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B (h`~pb
String sURL; //File URL :T6zT3(")D
long nStartPos; //File Snippet Start Position Bk.`G)t
long nEndPos; //File Snippet End Position R.* k7-(;
int nThreadID; //Thread's ID S]T71W<i
boolean bDownOver = false; //Downing is over 2>x[_
boolean bStop = false; //Stop identical *S<I!7Q
FileAccessI fileAccessI = null; //File Access interface .'+JA:3R
N{RHbSa(
c\P}ZQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *WzPxQ_
{ h\)ual_r[j
this.sURL = sURL; jMR9E@>~E
this.nStartPos = nStart; KVoi>?a
this.nEndPos = nEnd; YP"%z6N@v
nThreadID = id; P:'y}a-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tx3p, X
} A1zV5-E/
k ;vOPcw
9<!??'@f
public void run() 86&r;c:
{ bw#\"uJ
while(nStartPos < nEndPos && !bStop) E9 #o0Di
{ '+^XL6$L
.b*-GWx
'i/"D8
try{ eBECY(QMQ
URL url = new URL(sURL); OH+2)X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %HZ!s `w_
httpConnection.setRequestProperty("User-Agent","NetFox"); [.G~5%974
String sProperty = "bytes="+nStartPos+"-"; 5=MM^$QG
httpConnection.setRequestProperty("RANGE",sProperty); 6l>016 x
Utility.log(sProperty); #zd}xla0]
p_3VFKq>0
q*J-ii
InputStream input = httpConnection.getInputStream(); y3V47J2o
//logResponseHead(httpConnection); x4_FG{AIu
BxxqzN+
!.{{QwZ
byte[] b = new byte[1024]; 4~:D7",Jn
int nRead; |-AR)Smt
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zf\It<zT5
{ P}p6{
nStartPos += fileAccessI.write(b,0,nRead); [;INVUwG^
//if(nThreadID == 1) 0ipYXbC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dI8y}EbE~
} ws}>swR,
Cd'SPaR
;%i.@@:IQ
Utility.log("Thread " + nThreadID + " is over!"); hRN>]e,!
bDownOver = true; n)teX.ck)
//nPos = fileAccessI.write (b,0,nRead); TH}+'m
} Sh5SOYLz
catch(Exception e){e.printStackTrace ();} 3D7phq>.q
} Riz!HtyR
} <~qhy{hRn
[+$o`0q;N?
$3n@2 N`
//打印回应的头信息 n1)m(,{
public void logResponseHead(HttpURLConnection con) OK9D4 7X
{ %8GY`T:^
for(int i=1;;i++) BcTV5Wcr
{ )%5T*}j
String header=con.getHeaderFieldKey(i); =}AwA5G
if(header!=null) !tD,phca~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vo DTU]pf
Utility.log(header+" : "+con.getHeaderField(header)); q^w3n2
else >;@hA*<
break; ((%g\&D
} U~8 oE_+
} _-I0f##.
%sLij*
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public void splitterStop() K:eP Il{JE
{ U8KEg)Msk
bStop = true; &Qdd\h#
} i;>Hy|
az]S&\i7T
l0$ +)FKd
} uU]4)Hp
NN W*
<4Jo1
/* ?qQRA|n*
**FileAccess.java [ Q6v#I
*//文件访问(定位，写) GxGZxf*(
package NetFox; tXTa>Q
import java.io.*; eS jXaZh
=ITMAC\
~WJEH#
public class FileAccessI implements Serializable{ U>^-Db]
89'XOXl&1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &6E^<v?]
RandomAccessFile oSavedFile; M+ gYKPP
long nPos; bd2"k;H<o
s!2pOH!u
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public FileAccessI() throws IOException Au,}5=+`P
{ +S:(cz80V
this("",0); dOe|uQXyD
} fmvv q1G&
16YJQ ue
lfKrd3KS_
public FileAccessI(String sName,long nPos) throws IOException qf9.S)H1Z
{ %97IXrE
oSavedFile = new RandomAccessFile(sName,"rw"); @qH<4`y.^
this.nPos = nPos; XH0R:+s
oSavedFile.seek(nPos); CV4r31w
} Kl$!_$
n}yqpW!%n
eGblQGRS
public synchronized int write(byte[] b,int nStart,int nLen) #uT-_L}sw
{ 1k\1U
int n = -1; R)#D{/#FW
try{ #oi4!%*M
oSavedFile.write(b,nStart,nLen); 59p'Ega.
n = nLen; Vcl"qz@Fj
} 56AaviEC
catch(IOException e) 3Cwqy#X#8
{ ^Yn{Vi2.
e.printStackTrace (); c% 0h!zF
} w'.ny<Pe
Vrf` :%
~^IS{1
return n; 'd1E~A
} U,+kV?Z
r 06}@7
\p.Byso,
} *#frbV?;
KC?hsID{
+8Zt<snG
/* <<w $Ur
**SiteInfoBean.java GOa](oD}
*/ EH]5ZZ[Z
package NetFox; ^Y~ ,s
L;5jhVy
kte Dh7
public class SiteInfoBean { )AqM?FE4R
)-[ 2vhXz
i3*?fMxhu)
private String sSiteURL; //Site's URL D_9&=aa'
private String sFilePath; //Saved File's Path PQXyu1
private String sFileName; //Saved File's Name _jK\+Zf
private int nSplitter; //Count of Splited Downloading File C%"h1zWE:
}!& w<wR
V@84Cb
public SiteInfoBean() N*lq)@smq
{//nSplitter的缺省值为5 &.+[~2
//default value of nSplitter is 5 '9*wr*
this("","","",5); <=cj)
} fmA&1u/xMs
~DPg):cZ
r1-?mMSU&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R/b)hP~
{ PFG):i-?
sSiteURL= sURL; 8:L%-
sFilePath = sPath; 7-w +/fv
sFileName = sName; t_3)}
this.nSplitter = nSpiltter; I\Y/*u
AT+|}B!
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} L,waQk / @
Q2^}NQO=
`\q4z-<-
public String getSSiteURL() f>waFu-
{ h}z^NX
return sSiteURL; Trbgg
} o&;+!Si@T
27t:-O
RX=C)q2c
public void setSSiteURL(String value) MrLDe{^C2
{ mmTc.xh
sSiteURL = value; *u 3K8"XZ
} 9:fVHynr
z6|P]u
OjE wJ$$
public String getSFilePath() 5U3="L
{ 0}PW?t76
return sFilePath; ;'}1
} 3UD_2[aqN(
ub+>i
S=krF yFw
public void setSFilePath(String value) HP. j.
{ I#Iu:,OT
sFilePath = value; <z%zzc1s
} R7ZxS
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U,[vfSDGr
public String getSFileName() '<>pz<c
{ Rc0OEs%7P
return sFileName; '2uQ
} s7(mNpo
Z7K;~*
}4#%0x`w
public void setSFileName(String value) 4FGcCE3
{ L:XnW1(Or
sFileName = value; >e=tem~/
} HS="t3
_+ oX9
zK k;&y|{
public int getNSplitter() 'F5&f9A
{ _?Rprmjx}
return nSplitter; ^7Z)/c`"
} lyF~E
,l&Dt,
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public void setNSplitter(int nCount) D;.-e
{ [Sg1\UTl
nSplitter = nCount; zy
} +]Po!bN@@
} h-<('w:A
P`@d8%*;
^0pd- n@pn
/* sn@gchO9s
**Utility.java )_,*2|b
*/ k_ UY^vz.
package NetFox; 4~P{H/]
L1VUfEG-
;v^tUyhCb
public class Utility { 2h IM!wQ
)c^Rc9e/
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public Utility() \5_+6
{ W.r0W2))(
VY<$~9a&1
(Dlh;Ic r9
} SGXXv
;ug&v C
//线程睡眠 fFMGpibkM
public static void sleep(int nSecond) ^vn8s~#
{ )^qM%k8
try{ 3=RVJb
Thread.sleep(nSecond); Q})x4
} Qj.]I0d
catch(Exception e) ^HgQ"dD <
{ Ew5(U`]
e.printStackTrace (); 0M7Or)qN
} '-oS=OrZ
} ;PCnEs
!8lG"l|,l
//日志 .vE=527g)
public static void log(String sMsg) i ?&t@"'
{ 0x7F~%%2
System.err.println(sMsg); {;4Y5kj
} IppzQ0'=y1
8n+&tBq1
Zyt,D|eWj
public static void log(int sMsg) 0{^@kxV
{ W/!M eTU&E
System.err.println(sMsg); N[~{'i
} 6i|5`ZO
} ,V1/(|[h
m?'H7cFR
,n<t':-
/* ZG[P?fM
**TestMethod.java $0$'co"
*/ 1/X@~
package NetFox; I,TJV)B
~QgyhJM_h=
`B6*wE-|
public class TestMethod { cq lA"Eof
4wYD-MB
(3cJ8o>&
public TestMethod() iO1ir+B\
{ ///xx/weblogic60b2_win.exe ).U\,@[A{
try{ a%| I'r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Loz5[L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `_%UK=m
SiteFileFetch fileFetch = new SiteFileFetch(bean); CD]hi,B_J
fileFetch.start(); !%MI9Ok
} T8<pb^#
catch(Exception e){e.printStackTrace ();} DJ_[{WAV
>QyJRMY
W*J_PL9j
} Pq\ `0/4_
0lpkG ="&r
r-^FM~Jp
public static void main(String[] args) )/HbmtXqI
{ xgDd5`W
new TestMethod(); -R%T Dx
} a ?D]]0%
} (=A61]yB
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