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)); v>0xHQD*<M
} TX8,+s+
for(int i=0;i<nEndPos.length-1;i++) Xt9?7J#\T
{ %.[GR
nEndPos = nStartPos[i+1]; KWhw@y-5j@
} eGnc6)x@C
nEndPos[nEndPos.length-1] = nFileLength; +mV4Ty
} ks'25tv}F
} R+, tn,<<
Q{mls
ZYkeW
//启动子线程 PZH]9[H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [)9bR1wh
for(int i=0;i<nStartPos.length;i++) ?u 9) GJO[
{ Gl}=Q7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :S?'6lOc(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y]M/oH
nStartPos,nEndPos,i); YceiP,!4?v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZK_IK)g
fileSplitterFetch.start(); )SUT+x(DU
} m5f/vb4l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A-.jv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [4(TG<I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v@"xEf1n[
nEndPos = " + nFileLength); RR^I*kRH
// fileSplitterFetch[nPos.length-1].start(); 0B1*N_.L@
$5cLhi"`
}q27M
//等待子线程结束 #).om*Xh
//int count = 0; /3rt]h"
//是否结束while循环 bIe>j*VPh@
boolean breakWhile = false; Lj({ T'f(
H6rWb6i
?$F:S%eH
while(!bStop) 0XL x@FYn
{ {EZ ;
write_nPos(); ]@M$.msg@
Utility.sleep(500); .|KxQn}
breakWhile = true; -twIF49
GVn7#0x
5GT,:0
for(int i=0;i<nStartPos.length;i++) ZK3?"|vhC
{ #.a4}ya19
if(!fileSplitterFetch.bDownOver) =4+UX*&i?.
{ kw|bEL9!u
breakWhile = false; <hQ@]2w$
break; \L6U}ZQ2V
} (/Z~0hA[Q
} @T]gwJ
if(breakWhile) QBY7ZT05Gt
break; d*8 c,x
B>#zrCD
>x&$lT{OY
//count++; `Z]a6@w~
//if(count>4) /]<0`nI.
// siteStop(); VLu_SXlo*
} RiaO`|1
EmG`ga)s
LQNu]2
System.err.println("文件下载结束！"); m7^a4
} g|e^}voRM
catch(Exception e){e.printStackTrace ();} #qm<4]91
} ks sXi6^
u\&oiwSIP
n4(w?,w}
//获得文件长度 ANp4yy+
public long getFileSize() -5kq9Dy\,
{ sVaWg?=qs'
int nFileLength = -1; "op1xto
try{ kH1l -mxz
URL url = new URL(siteInfoBean.getSSiteURL()); !bT0kP$3}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~$!eB/6ty
httpConnection.setRequestProperty("User-Agent","NetFox"); !);}zW!
SU2(XP]5
(al7/EhY
int responseCode=httpConnection.getResponseCode(); QH~/UnV
if(responseCode>=400) $:/y5zi
{ ^yH|k@y
processErrorCode(responseCode); NQ@ EZoJ
return -2; //-2 represent access is error T?^AllUZQR
} aW4tJN%!
o(C({]UO/
WO^smCk
String sHeader; ./J.OU1
OQW#BBet@
1\kOjF)l
for(int i=1;;i++) 6<sB
{ dq"b_pr;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1}KNzMHk9
//Utility.log(in.readLine()); (3c,;koRR
sHeader=httpConnection.getHeaderFieldKey(i); _Vj O [hx
if(sHeader!=null) :[|`&_D9J
{ a5L#c=
if(sHeader.equals("Content-Length")) 'rp(k\pY
{ J Y %B:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qC.jXU?rO
break; ;QREwT~H
} >:Xzv
} ZCbxL.fFz
else m$pXe<
break; 3`IDm5
} L~I<y;x
} Y?ZTl762
catch(IOException e){e.printStackTrace ();} n?!.r c
catch(Exception e){e.printStackTrace ();} ')Ozz<{
u0w2v+
;=*b:y Y
Utility.log(nFileLength); )8st
zd>[uIOR
]A9Vh
return nFileLength; .y+>-[j?B
} MvL%*("4b
Q:>;d-D|1
zP rT0
//保存下载信息（文件指针位置） `lN1u'(:
private void write_nPos() 8Tt2T} Y
{ <)?H98S
try{ {BY`Wu:w
output = new DataOutputStream(new FileOutputStream(tmpFile)); q|=tt(}G
output.writeInt(nStartPos.length); K]N^6ome
for(int i=0;i<nStartPos.length;i++) 6\OSIxJZF
{ &"Ua"H)
// output.writeLong(nPos); K)l{3\9l|
output.writeLong(fileSplitterFetch.nStartPos); "*kWM
output.writeLong(fileSplitterFetch.nEndPos); |KplbU0iC
} TjgX' j
output.close(); b;9v.MZ4>g
} 7{v0K"E{
catch(IOException e){e.printStackTrace ();} @T?:[nPf&F
catch(Exception e){e.printStackTrace ();} R4E0avt
} .<rL2`C[c
;# {XNq<1
[WY NA-O
//读取保存的下载信息（文件指针位置） (<itE3P
private void read_nPos() ]/JE#
{ A9p$5jt7
try{ c c ,]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HP*x?|4
int nCount = input.readInt(); jR}h3!
nStartPos = new long[nCount]; 1#aOgvf
nEndPos = new long[nCount]; E)#3*Wlu$
for(int i=0;i<nStartPos.length;i++) D'|#5>G
{ vyN=X]p
nStartPos = input.readLong(); AN$}%t"
nEndPos = input.readLong(); Itj|0PGd
} >fdS$,`A
input.close(); W-7yi`5
} *ZKfyn$+~
catch(IOException e){e.printStackTrace ();} u9N?B* &{
catch(Exception e){e.printStackTrace ();} O 4l[4,`
} 0N_Ma')i
nU[ROy5
h"#^0$f
private void processErrorCode(int nErrorCode) 0Q]x[;!k
{ - Kj$A@~x
System.err.println("Error Code : " + nErrorCode); ,UH`l./3DX
} o=w&&B
PKwHq<vAsB
<4rF3 aB-
//停止文件下载 ;G;vpl
public void siteStop() e9k}n\t3
{ 2ZNTg@o
bStop = true; 2X]2;W)S;
for(int i=0;i<nStartPos.length;i++) g#9KG
fileSplitterFetch.splitterStop(); wgkh}b
Ju)2J?Xs5
Ij@YOt
} ~" }t8`vP1
} 0-l @U{
//负责部分文件的抓取 dH&N<
**FileSplitterFetch.java ?!Rlp/
*/ k{y@&QNj
package NetFox; .;/@k%>
7KuTC%7
'#u|RsZ
import java.io.*; DWm$:M4z
import java.net.*; A}H)ojG'v
N$:[`,
Z^>3}\_v
public class FileSplitterFetch extends Thread { wH{lp/
c6E@+xU
JgYaA*1X
String sURL; //File URL KB*[b
long nStartPos; //File Snippet Start Position #E{OOcM
long nEndPos; //File Snippet End Position ldI;DoE#U1
int nThreadID; //Thread's ID )h2wwq0]
boolean bDownOver = false; //Downing is over _9\ayR>d
boolean bStop = false; //Stop identical QOy+T6en
FileAccessI fileAccessI = null; //File Access interface DH)@8)C
niqiDT/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _2}i8q:
{ &wK%p/?
this.sURL = sURL; CIj3D"
this.nStartPos = nStart; c<pr1g
this.nEndPos = nEnd; [M Z'i/
nThreadID = id; IUbYw~f3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2[qO;js
} X/2Xr(z"k
{xr4CDP
LPO3B W
public void run() `)1_^# k
{ ZfL\3Mn
while(nStartPos < nEndPos && !bStop) HMrS::
{ _4xX}Z;
Tx`;y|
"eZNci
try{ z)]_(zZ^
URL url = new URL(sURL); 7=Ew[MOmM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S=eY`,'#R
httpConnection.setRequestProperty("User-Agent","NetFox"); ~Q>97%
String sProperty = "bytes="+nStartPos+"-"; #f\U3p
httpConnection.setRequestProperty("RANGE",sProperty); vZhN% DfY
Utility.log(sProperty); oPo<F5M]d%
x)THeH@
M=`F $
InputStream input = httpConnection.getInputStream(); /DQoM@X
//logResponseHead(httpConnection); 9_KUUA
w# ,:L)
>9uDY+70I3
byte[] b = new byte[1024]; hi`\3B
int nRead; FL/@e$AK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "9&6bBa
{ T&w3IKb|}
nStartPos += fileAccessI.write(b,0,nRead); 4F)z-<-b
//if(nThreadID == 1) .!l#z|/x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); az?B'|VX
} QVb@/
~ NKw}6
2\CFt;fk
Utility.log("Thread " + nThreadID + " is over!"); Z[ZqQ` 7N
bDownOver = true; !@W1d|{lu
//nPos = fileAccessI.write (b,0,nRead); ~BDVmQa
} 'fy1'^VPAV
catch(Exception e){e.printStackTrace ();} ;oH%d;H
} u6awcn
} |Y0BnyGK
]y2(ZTNTs
R1 hb-
//打印回应的头信息 7t0\}e
public void logResponseHead(HttpURLConnection con) R1{"
{ mxGa\{D#y
for(int i=1;;i++) vd9l1"S
{ `~(KbH=]
String header=con.getHeaderFieldKey(i); ;rV0
if(header!=null) [^8*9?i4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tceQn ^|<
Utility.log(header+" : "+con.getHeaderField(header)); 5m=3{lBi
else *&% kkbA
break; 8ooj)
} 9"I/jd0B
} TStu)6%`
TsfOod
P%ev8]2
public void splitterStop() #J\ 2/~
{ ++5W_Ooep
bStop = true; )o SFHf
} =V/$&96Q
: \:jIP
O<)"kj 7
} m!$"-nh9
]9l=geZd%;
c03A_2%
/* 4 "@BbVYR
**FileAccess.java ,fT5I6l
*//文件访问(定位，写) S^c5
package NetFox; RI')iz?
import java.io.*; vaxNF%^~yN
8N'`kd~6[
q/6d^&
public class FileAccessI implements Serializable{ kK16+`\+
cr27q6_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vMRM/.
RandomAccessFile oSavedFile; |F iL1_
long nPos; i(a2FKLy
z5=&qo|f9l
"qu%$L
public FileAccessI() throws IOException z%hB=V!~91
{ ;v[F@O~*)
this("",0); dScit!T"
} Io|NL6[
B=(m;A#G
lw\OsB$
public FileAccessI(String sName,long nPos) throws IOException ;E,%\<
{ 0N;Pb(%7UU
oSavedFile = new RandomAccessFile(sName,"rw"); "e&S*8QhM
this.nPos = nPos; k =ru) _$2
oSavedFile.seek(nPos); z%}^9
} (fUXJ$
/E2/3z
:y"Zc1_E
public synchronized int write(byte[] b,int nStart,int nLen) j\P47q'v#
{ w3:Y]F.ot
int n = -1; JY"<b6C^
try{ #c5G"^)z
oSavedFile.write(b,nStart,nLen); NFDi2L>Ba
n = nLen; Y`uL4)hR5
} A%Pjg1(uX
catch(IOException e) &\F`M|c
{ g|9'Lk
e.printStackTrace (); R.Ao%VT
} 8*V3g_z
Co4QWyt:
_ncqd,&z
return n; '&I.w p`^
} t9Ht 54
Sl/[9-a)
d(jd{L4d
} w-Y-;*S
ZL:nohB
+Tf,2?O
/* :tu6'X\k
**SiteInfoBean.java 63#Sf$p{v
*/ &y[Od{=
package NetFox; j="{^b
1[ ME/r
z:ue]7(.
public class SiteInfoBean { HpiP"Sl
C:"Al-
y[UTuFv~Q
private String sSiteURL; //Site's URL npkE[JE:
private String sFilePath; //Saved File's Path yEJ}!/
private String sFileName; //Saved File's Name EEEYNu/4/
private int nSplitter; //Count of Splited Downloading File <{Wsh#7}.
il(dVW
c`yLn%Of%
public SiteInfoBean() 9fp1*d
{//nSplitter的缺省值为5 [[}KCND
//default value of nSplitter is 5 QmvhmsDL
this("","","",5); ArDkJ`DE
} vrXUS9i.
%G1kkcdH<
B<SuNbR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )[|`-M~u
{ Smzy EMT
sSiteURL= sURL; g)u ~GA*=
sFilePath = sPath; iq)4/3"6
sFileName = sName; y/Fv4<X
this.nSplitter = nSpiltter; oyZ}JTl(Q
<5?.s< y$"
FX`SaY>D
} h|$.`$
Kr3L~4>
9+)5#!0
public String getSSiteURL() aF7" 4^P
{ l~kxt2&
return sSiteURL; (, Il>cR4
} vn}:$|r$J
l`G .lM(
7E*d>:5I
public void setSSiteURL(String value) R=yn4>I
{ `rzgC \
sSiteURL = value; :@a8>i1&
} hg_@Ui@[z
&k*sxW'
wWB-P6
public String getSFilePath() yANk(
{ ~Wp>tnl
return sFilePath; Oz<{B]pEul
} ^ ry
w~wpm7
n@<+D`[.V
public void setSFilePath(String value) FO#`}? R`
{ V`sINX
sFilePath = value; uO8z.
} DUUQz:?{J
>0z(+}]3z
M@ILB-H
public String getSFileName() bq#*XCt#
{ G9J+D?'hH
return sFileName; Sz|;wsF{
} P~/Glak
dr#g[}l'H
?s/]k#H
public void setSFileName(String value) ~UA:_7#\M
{ ;WxE0Q:!~
sFileName = value; x8YuX*/I
} 'o;>6u<u
V+myGsr`
oh c/{D2
public int getNSplitter() 4n_f7'GZg
{ mcvd/
return nSplitter; 7~n<%q/6
} ANh7`AUuO
~ HFDX@m*
'au7rX(
public void setNSplitter(int nCount) N) D;)ZH
{ w-9M{Es+j
nSplitter = nCount; Gxx:<`[ON
} ^GMM%
} `IL''eJug_
V`Ve__5;
Rg@W0Bc)
/* Y|$3%t
**Utility.java WfYu-TK*
*/ *F7ksLH|q
package NetFox; AG/?LPJ
OE_;i}58
|t](4
public class Utility { /sVy"48-
1 XsB
B=?4; l7
public Utility() E{+V_.tlu
{ Qv=F'
N6yPuH
do0;"O0 (
} 5H8]N#Y&
pV`?=[h9
//线程睡眠 MD`1KC_m
public static void sleep(int nSecond) uXD?s3Wv
{ GR6BpV7
try{ q{v?2v{
Thread.sleep(nSecond); h^QicvZ
} IjJO;
catch(Exception e) x xMV2&,Jq
{ it?l! ~
e.printStackTrace (); 2eNA#^T=
} RE~:+.eB
} \H <k
Y v22,|:
//日志 &)Y26*(`
public static void log(String sMsg) HAa$pGb
{ 5`];[M9
System.err.println(sMsg); E2J.t`H
} !58j xh
qRy<W
T#&tf^;
public static void log(int sMsg) gG5@ KD6k
{ *htv:Sr
System.err.println(sMsg); ,|RS]I>X
} )y8 u+5^
} ?8dd^iX/
;.Dm?J0
v 809/c*
/* s'/b&Idf8
**TestMethod.java #bk[Zj&
*/ i4"BN,NZ{
package NetFox; xB.h#x>_`
rO#WG}E<"
="X2AuK%1$
public class TestMethod { Z*,Nt6;e
mWhQds6
'L$%)`;e
public TestMethod() jpg$5jZ
{ ///xx/weblogic60b2_win.exe sJA` A
try{ jvGGIb"&1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ey4RKk,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %p?+r
SiteFileFetch fileFetch = new SiteFileFetch(bean); ean_/E
fileFetch.start(); K7o!,['W
} f;";P
catch(Exception e){e.printStackTrace ();} aB@D-Y"HO
{{'GR"D
=Yd{PZ*fR
} Hrz#So\#
9/[1a_ r
|"7F`M96I
public static void main(String[] args) OB-gH3:
{ *>b*I4dz
new TestMethod(); |Dz$OZP
} u7L!&/6On
} >\J({/ #O
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