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)); 5X:3'*
} rW`l1yi*$
for(int i=0;i<nEndPos.length-1;i++) 2fP;>0?
{ CM)V^k*
nEndPos = nStartPos[i+1]; c9+yU~(
} s$ ?;C
nEndPos[nEndPos.length-1] = nFileLength; U"a7myB+jX
} ,?wxW
} Y.%Vvg4z3
=:\5*
8qoA5fW>
//启动子线程 E|W7IgS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Qu-X\
for(int i=0;i<nStartPos.length;i++) KIY9?B=+
{ d"thM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DkW^gt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P[r$KGz
nStartPos,nEndPos,i); IaO*{1re
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \xmDkWzE
fileSplitterFetch.start(); kR{$&cE^
} R0-Y2v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `)Y 5L}c=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Jv!f6*&<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o Va[
nEndPos = " + nFileLength); OXbC\^qo@
// fileSplitterFetch[nPos.length-1].start(); 3A\Z]L
mB%m<Zo\U
GK#D R/OM
//等待子线程结束 Is9.A_0h
//int count = 0; A>\3FeU>UC
//是否结束while循环 "+hUt
boolean breakWhile = false; gl!ht@;>ak
\!*F:v0g^
%1)JRc
while(!bStop) Hro)m"
{ 5[~C!t;
write_nPos(); UU '9
Utility.sleep(500); ^}lL@Bd|
breakWhile = true; kH=qJ3Z
.ZM0cwF
#;UoZJ B
for(int i=0;i<nStartPos.length;i++) ,2P/[ :
{ &uI33=
if(!fileSplitterFetch.bDownOver) qipS`:TER
{ >E WK cocM
breakWhile = false; #r]GnC,
break; |C>\ku*
} D2zqDo<+;
} R9UC0D:-x
if(breakWhile) ^[v>B@p*{
break; oUB9)C~
`R*!GHro
!ED,'d%J
//count++; @Y#TWt#
//if(count>4) ]Nue1xV_
// siteStop(); f|2QI~R
} ?S.LGc
?yA 2N;
5e2yJ R
System.err.println("文件下载结束！"); mOb@w/f
} Qd}h:U^
catch(Exception e){e.printStackTrace ();} yaAg!mW
} V_KHVul
sO)!}#,
0p'g+ 2
//获得文件长度 p&HkR^.S
public long getFileSize() }mS+%w"j
{ <O{G&
int nFileLength = -1; (dym*_J
try{ $-gRD|oY
URL url = new URL(siteInfoBean.getSSiteURL()); "rw'mogRL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /q^_ 'Lp
httpConnection.setRequestProperty("User-Agent","NetFox"); pH0MVu(W
MED_#OS
N Q}5'
int responseCode=httpConnection.getResponseCode(); W;8}`k
if(responseCode>=400) QtOT'<2t]
{ q{7+N1 "
processErrorCode(responseCode); ^1XnnQa
return -2; //-2 represent access is error (-{.T
} [O6JVXO>
&lW~ot1,
xic&m5j m
String sHeader; #}8gHI-9%
K Z0%J5
jDW$}^ 6
for(int i=1;;i++) > Cx;h=
{ a<Ps6'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wE_#b\$=b
//Utility.log(in.readLine()); gR k+KGKn<
sHeader=httpConnection.getHeaderFieldKey(i); }do=lm?/
if(sHeader!=null) @FuX^Q.[
{ HE3x0H}o>
if(sHeader.equals("Content-Length")) Y^,G} &p
{ h>n<5{zqM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +Z/aG k;
break; T?8N$J
} m# I
} u]t#Vf-$u
else 9icy&'
break; 9jrlB0
} h?&S*)1
} 3d>xg%?
catch(IOException e){e.printStackTrace ();} (s!cd]Qa.
catch(Exception e){e.printStackTrace ();} 3HB(rTw
zY\MzhkX,
YnX6U1/^
Utility.log(nFileLength); O%busM$P)/
%2rUJaOgy$
sTFRu
return nFileLength; wfBf&Z0{
} ~@EBW3>~5
-wn(J5NnR
F$H^W@<w
//保存下载信息（文件指针位置） O.wk*m!9
private void write_nPos() w_^g-P[o-
{ l|~SVk|
try{ Z/=HQ8
output = new DataOutputStream(new FileOutputStream(tmpFile)); HXRK<6k$
output.writeInt(nStartPos.length); .5?Md
for(int i=0;i<nStartPos.length;i++) #wZBWTj.
{ p+|(lrYC
// output.writeLong(nPos); 1N\-Ku
output.writeLong(fileSplitterFetch.nStartPos); bY7~b/
output.writeLong(fileSplitterFetch.nEndPos); YNWAef4
} +#0,2wR#
output.close(); /,#&Htk
} BX6]d:S
catch(IOException e){e.printStackTrace ();} 7Ys\=W1
catch(Exception e){e.printStackTrace ();} 5nJmabw3
} 334tg'2]
V/i7Zh#2:
+b6kU{
//读取保存的下载信息（文件指针位置） !)TO2?,^
private void read_nPos() Na2n4x!
{ (.54`[2+L
try{ 5Rec~&v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Sej\Gt
int nCount = input.readInt(); E;C=V2#>[
nStartPos = new long[nCount]; /J0ctJ2k
nEndPos = new long[nCount]; Fl&Z}&5p
for(int i=0;i<nStartPos.length;i++) ^\zf8kPti
{ ti^msC8e
nStartPos = input.readLong(); \LZVazXD
nEndPos = input.readLong(); - d(RK_
} SRf.8j
input.close(); G%RhNwm
} mBZg(TY
catch(IOException e){e.printStackTrace ();} |Y\BI^
catch(Exception e){e.printStackTrace ();} 3"J85V%h]n
} l\{{iAC]I
-?&s6XA%#
5 NdIbC
private void processErrorCode(int nErrorCode) iH""dtO
{ A('_.J=
System.err.println("Error Code : " + nErrorCode); O*zF` 9
} fA>FU/r
#'jd.'>
KQ(7%W
//停止文件下载 1P+Te,I
public void siteStop() i VIpe
{ b#[7A
bStop = true; IHlTp0?
for(int i=0;i<nStartPos.length;i++) lwuslt*E/
fileSplitterFetch.splitterStop(); \a}W{e=FNT
`;fk,\8t%
=/jCDY
} z4yV1
} c_YP#U
//负责部分文件的抓取 5U+a{oA
**FileSplitterFetch.java XKq}^M&gy
*/ <X,0\U!lL
package NetFox; 8~")9w
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nd/.]"
import java.io.*; dNMz(~A[Y
import java.net.*; Y"&1jud4xl
O A9G] 8k
*(sUz?t
public class FileSplitterFetch extends Thread { }yW*vy6`
=`MU*Arcs[
v{dvB:KP5X
String sURL; //File URL pl.K*9+
long nStartPos; //File Snippet Start Position QirS=H+~
long nEndPos; //File Snippet End Position ?pJUbZ#J
int nThreadID; //Thread's ID ;jgJI~3l
boolean bDownOver = false; //Downing is over zU1[+JJY"{
boolean bStop = false; //Stop identical @s2<y@
FileAccessI fileAccessI = null; //File Access interface M:? :EJ
f^63<gqY
S=bdue
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^Gs=U[**
{ ?nya;Z-~Hc
this.sURL = sURL; .:)nG(7f<
this.nStartPos = nStart; *3>$f.QU
this.nEndPos = nEnd; y! lEGA7
nThreadID = id; BRg(h3 ED
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^cy.iolt
} 'U"ub2j
(?7=$z!h
gZD,#D.hR
public void run() dUg| {l
{ GcL:plz
while(nStartPos < nEndPos && !bStop) {tlt5p!4
{ <!r0[bKz@
yj48GQP]
&CEZ+\bA
try{ "}jY;d#n
URL url = new URL(sURL); =(x W7Pt~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zsZP\
httpConnection.setRequestProperty("User-Agent","NetFox"); $stBB
String sProperty = "bytes="+nStartPos+"-"; u(!@6%?-
httpConnection.setRequestProperty("RANGE",sProperty); J^R#
Utility.log(sProperty); L,B#%t
aF~ 0\XC
{IlX@qWr
InputStream input = httpConnection.getInputStream(); `1eGsd,f
//logResponseHead(httpConnection); z`:uvEX0
JWuF ?<+k
!VJ5(b
byte[] b = new byte[1024]; 9<ev]XaSl
int nRead; rprtp5Cg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xxN=,p
{ wwtk6;8@
nStartPos += fileAccessI.write(b,0,nRead); mz~aSbb|
//if(nThreadID == 1) 0DFxVH_xN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mar BVFz~
} eaI!}#>R+
P{-f./(JD
UF)4K3X
Utility.log("Thread " + nThreadID + " is over!"); #l!Sz247
bDownOver = true; KF#,Q
//nPos = fileAccessI.write (b,0,nRead); 3'H 1T
} y~cDWD<h
catch(Exception e){e.printStackTrace ();} *Q@%<R
} ^mu?V-4
} >lRa},5(
_k,/t10
^\X-eeA
//打印回应的头信息 Yb<t~jm
public void logResponseHead(HttpURLConnection con) I<'wZJRRa
{ Y GZX}-
for(int i=1;;i++) FD&"k=p+X
{ '01ifA^
String header=con.getHeaderFieldKey(i); ,KMt9<
if(header!=null) %S<0l@=5`l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Co*"hl>2
Utility.log(header+" : "+con.getHeaderField(header)); +s}"&IV%
else Q599@5aS
break; m2YsE j7
} Fq!_VF^r
} w El-
[)dIt@Y&j
?E(X>tH
public void splitterStop() `u R`O9)e
{ aG]^8`~>'
bStop = true; KZ%us6
} (;^>G[
GQJ4d-w
s$(%?,yf2
} r:g_mMvB
zUNUH^Il
:<k (y?GB
/* nHH FHnFf
**FileAccess.java 9$U4x|n
*//文件访问(定位，写) W}2!~ep!
package NetFox; 6O.kKhk
import java.io.*; (9TSH3f?
Z h9D^I
Iu~<Y(8^q#
public class FileAccessI implements Serializable{ 5o>*a>27,A
vF pKkS343
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7jQVm{{.
RandomAccessFile oSavedFile; #qR6TM&;
long nPos; 5XzsqeG|
A+frKoi
ZZHzC+O#^
public FileAccessI() throws IOException Iz'Et'w8!
{ sKsMF:|OT
this("",0); @iXBy:@
} a j$& 9][
8O(L;&h
tLN^k;w
public FileAccessI(String sName,long nPos) throws IOException 3 =c#LUA`
{ ;m>/tD%
oSavedFile = new RandomAccessFile(sName,"rw"); wfEL .h
this.nPos = nPos; ~e]B[>PT
oSavedFile.seek(nPos); }&v-<qC^
} HwZl"!;Mry
HC1<zW[
' (XB|5
public synchronized int write(byte[] b,int nStart,int nLen) *]h"J]
{ 2<p@G#(
int n = -1; k9<UDg_ Y
try{ E i>GhvRM
oSavedFile.write(b,nStart,nLen); WiB~sIp
n = nLen; 6OAEAIh
} B:0oT
catch(IOException e) aPK:k$.
{ :8@eon}
e.printStackTrace (); j (Q#NFT7
} OI"g-+~
~m,~;
h(~/JW[
return n; )"hd"
} -y|']I^ &
jAue+tB
%#~wFW|]x
} CDXN%~0h
T0"nzukd
>3B{sn}
/* 7CSz
**SiteInfoBean.java izGU&VeB
*/ }$L1A
package NetFox; Q_!tn*
2#3`[+g<n
<H-kR\HF
public class SiteInfoBean { C4`&_yoP4-
ai1;v@1
G3+e5/0
private String sSiteURL; //Site's URL 89GW!
private String sFilePath; //Saved File's Path S;gy:n!t
private String sFileName; //Saved File's Name QKx(S=4jQ
private int nSplitter; //Count of Splited Downloading File o#1Ta7Ro
&"gX 7cK8
bc~$"
public SiteInfoBean() 9&Un|cr
{//nSplitter的缺省值为5 cn/&QA"
//default value of nSplitter is 5 ~6Fh,S1?
this("","","",5); 8-7Ml3G*
} EW vhT]<0
+HRtuRv0T
=q)+_@24>d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (Cq 38~mR
{ ?wv3HN
sSiteURL= sURL; Vn:v{-i
sFilePath = sPath; \9tJ/~
sFileName = sName; +;,J0,Yn
this.nSplitter = nSpiltter; WQ.{Ag?1
t?)]xS)
8IWT;%
} 1@ &J"*
dmv0hof
&08dW9H
public String getSSiteURL() Lb<IEy77\
{ x|Pz24yP9
return sSiteURL; jPZ+~:m+
} n7~4*B
((#BU=0iK
NB'G{),)Z
public void setSSiteURL(String value) nvLdgu4P>
{ Qjnh;uBO
sSiteURL = value; IAMa
} -AD`(b7q
'%ZKvZ-
_Li.}g@Bd
public String getSFilePath() He4HIZ
{ qzA_ ~=g
return sFilePath; $kHXt]fU
} 7t#Q8u?
wme#8/eUk
4guR8 elM
public void setSFilePath(String value) t\ z@k9
{ X(Mpg[,N"
sFilePath = value; w/*#TDR
} qN' 3{jiPL
7G;1n0m-T
ml^=y~J[
public String getSFileName() :=+YZ|&j
{ a3w6&e`
return sFileName; Fq <JxamR
} I~YV&12
`uk=2k}&m
GYb&'#F~t
public void setSFileName(String value) fK]%*i_"
{ CMbID1M3
sFileName = value; |.yS~XFJS
} _[(EsIqc(F
Pw]r&)I`y[
nsXG@CS:
public int getNSplitter() z)v o
{ LWhy5H;Es
return nSplitter; [*(1~PrlO,
} 1BW9,Xr
jVOq/o
?f3R+4
public void setNSplitter(int nCount) B=%%3V)2
{ C{nk,j L
nSplitter = nCount; Akc |E!V
} LH+Bu%s
} RyukQY~<W
3]lq#p:
RdyKd_0`Q
/* 0F_hXy@K
**Utility.java sKKc_H3YSH
*/ fH_l2b[-3@
package NetFox; ;r6YIS4@
;~$Q;m1
h@1/
public class Utility { M[O22wFs
)!E:
L;vglS=l;
public Utility() {:_*P TVk
{ =?+w5oI0
T95FoA
9ei'oZ
} !ii(2U
\}kR'l
//线程睡眠 gpzFY"MS=
public static void sleep(int nSecond) .mqMzV
{ NX(+%EBcA
try{ %x@bP6d[
Thread.sleep(nSecond); Eul3 {+]
} s 72yu}
catch(Exception e) &FOq c
{ /y4A?*w6
e.printStackTrace (); "SQyy
} NJd4( P
} gp 11/.
Q7F4OS5b
//日志 HGh)d` 8
public static void log(String sMsg) nSQ]qH&4d
{ Q"eqql<h#
System.err.println(sMsg); >c Tt2v
} 3$K[(>s
[okV[7
Kx,X{$Pe
public static void log(int sMsg) sm G?y~
{ TxN+-< f
System.err.println(sMsg); WL'!M&h
} dQ_'8 )
} NM),2%<
hSAI G
:@E^oNKa0
/* <?L5bhq
**TestMethod.java EW4a@
*/ + `'wY?
package NetFox; CK4#ZOiaa
jgXr2JQ<
&dj/Dq@
public class TestMethod { Gf.xr%mUZr
nZL!}3@<
+Lc+"0*gV*
public TestMethod() 'Pn:10;
{ ///xx/weblogic60b2_win.exe fy$CtQM
try{ GyxLzrp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !H c6$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &6Lh>n(
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^b$G.h{o!E
fileFetch.start(); Xm(#O1Vm(l
} %t1Z!xv_
catch(Exception e){e.printStackTrace ();} >,k2|m
u6Ux nqNc
#wvGS%
} 7J$rA.tu
(M{wkQTO
|d6/gSiF
public static void main(String[] args) ;O,&MR{;|n
{ =)i^E9
new TestMethod(); Y Kp@n8A
} L.K|]]u
} a5pM~.]
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