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)); )Q1aAS3
} *o1US
for(int i=0;i<nEndPos.length-1;i++) >|S@twy
{ 3nBZ+n4z
nEndPos = nStartPos[i+1]; p7\LLJ y
} ]2u
nEndPos[nEndPos.length-1] = nFileLength; tE0{ae
} Nd(3q]{
} +VVn@=&?
">T\]V$R
-+F,L8
//启动子线程 &/m^}x/_W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !=S?*E +j)
for(int i=0;i<nStartPos.length;i++) o"Xv)#g&
{ ^m7y=CJM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4lPO*:/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ln_&Ux+l
nStartPos,nEndPos,i); <Ve0PhK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /@ emE0
fileSplitterFetch.start(); W(s5mX,Kv
} 1*A^v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bF9.k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &Sb)a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zgFL/a<
nEndPos = " + nFileLength); L%H\|>k`
// fileSplitterFetch[nPos.length-1].start(); `Ku:%~$/
Uic
aMu6{u6
//等待子线程结束 gjsks(x
//int count = 0; e<+)IW:
//是否结束while循环 E3a^"V3p
boolean breakWhile = false; ok6t| 7sq
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{_tq6ja-<
while(!bStop) ~_i=hx
{ ms3"
write_nPos(); 7x.j:{2
Utility.sleep(500); yVVyWte,
breakWhile = true; 0(o2<d7
J#:`'eEG
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for(int i=0;i<nStartPos.length;i++) S.[L?uE~F
{ B _ J2Bf
if(!fileSplitterFetch.bDownOver) e 6wevK\
{ @ddCVxd
breakWhile = false; @D[+@N
break; K!AA4!eUzM
} h}|.#!C3
} i~E0p ,
if(breakWhile) U;kNo3=
break; fhn$~8[_A
6 _V1s1F
'hu'}F{
//count++; CE{2\0Q
//if(count>4) Cn=#oE8(A
// siteStop(); a`:F07r
} xrXfZ>$5bM
A1;'S<a
9b6U]z,
System.err.println("文件下载结束！"); },X.a@:
} ouyZh0G
catch(Exception e){e.printStackTrace ();} 7[ n |3
} >KQ/ c
> {d9z9O
$ r-rIW5\
//获得文件长度 cSv;HN:
public long getFileSize() uEhPO
{ 3-AOB3](
int nFileLength = -1; &hZ.K"@7{
try{ %<8?$-[
URL url = new URL(siteInfoBean.getSSiteURL()); G,+3(C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <}.!G>X
httpConnection.setRequestProperty("User-Agent","NetFox"); ;y7+Q
:3s^, g
*yHz#u'
int responseCode=httpConnection.getResponseCode(); yzl}!& E
if(responseCode>=400) j"Ew)6j
{ 3=?,Dv0P
processErrorCode(responseCode); InRRcn(
return -2; //-2 represent access is error *T}c{/
} C2b<is=H:
,ExY.'%1
7wY0JS$fz
String sHeader; !]fSS)\H
O`!XW8
`|&0j4(Pg
for(int i=1;;i++) 7/KK}\NE
{ vqVwo\oEdU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'ahZ*@kr
//Utility.log(in.readLine()); X,lhVT |
sHeader=httpConnection.getHeaderFieldKey(i); Xwu&K8q21
if(sHeader!=null) n``9H91
{ JSylQ201
if(sHeader.equals("Content-Length")) LOG>x!
{ ePR9r}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j4`+RS+q
break; 9D,!]
} j,9/eZRZ
} I(k(p\l%
else $tc1te
break; |#BN!kc
} ^xScVOdP
} L&=r-\.ev
catch(IOException e){e.printStackTrace ();} u(hJyo}
catch(Exception e){e.printStackTrace ();} 1`s^r+11:
6Z=Qs=q
e_l|32#/
Utility.log(nFileLength); (!efaj
TI2K_'
2qVoe}F
return nFileLength; 0DnOO0Nc
} f<oU"WM
zN)).a
Ek_<2!%X
//保存下载信息（文件指针位置） '-XO;{,-R
private void write_nPos() C CLc,r>)
{ UUvCi+W
try{ bVa?yWb.
output = new DataOutputStream(new FileOutputStream(tmpFile)); .kkhW8:
output.writeInt(nStartPos.length); 6]?W&r|0I
for(int i=0;i<nStartPos.length;i++) KW ZEi?
{ =\MAz[IDj
// output.writeLong(nPos); [#G*GAa6*
output.writeLong(fileSplitterFetch.nStartPos); ^wwS`vPb
output.writeLong(fileSplitterFetch.nEndPos); @Jqo'\~&
} M} ri>o
output.close(); d.Ccc/1-
} Wi,)a{
catch(IOException e){e.printStackTrace ();} G^.tAO5:f
catch(Exception e){e.printStackTrace ();} >lyE@S sA
} -eD]gm
}J-e:FUF#
1_;{1O+B
//读取保存的下载信息（文件指针位置） *(5T?p[7
private void read_nPos() D#`>p
{ 0%q H=do6
try{ se]&)%p[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -0]%#(E%`h
int nCount = input.readInt(); ?1O` Rd{tn
nStartPos = new long[nCount]; BG.sHI{
nEndPos = new long[nCount]; Z.x]6
for(int i=0;i<nStartPos.length;i++) 3Of!Ykf=
{ 9%"\s2T
nStartPos = input.readLong(); {Xr 9]g`
nEndPos = input.readLong(); |QR9#Iv
} ]Wjcr2Wq
input.close(); ;R<V-gab
} ,!PV0(F(
catch(IOException e){e.printStackTrace ();} B&1E&Cv_8
catch(Exception e){e.printStackTrace ();} f#7=N{wm
} s%>8y\MaK
{gD`yoPrV
q"S,<I<f
private void processErrorCode(int nErrorCode) lF40n4}
{ 9`"#OQPn1
System.err.println("Error Code : " + nErrorCode); F~7TE91C
} 5DkEJk7a
"3a}~J<g
?| 6sTu!
//停止文件下载 -okq=9
public void siteStop() F!4V!VWA}
{ (#)XRm{t
bStop = true; N>Uxq&)!
for(int i=0;i<nStartPos.length;i++) |;d#k+/;
fileSplitterFetch.splitterStop(); 4gVIuF*pS
CBpwtI>p
iE_[]Vgc
} ma<uXq
} 6R$Yh0%
//负责部分文件的抓取 o-AF_N
**FileSplitterFetch.java ]ZW-`UMO
*/ |B'4wF>
package NetFox; SXvflr] =m
xD~r Q$6sI
(plT/0=^t
import java.io.*; O,vC:av
import java.net.*; T{-gbo`Yji
1,]FLsuy
W!Hn`T
public class FileSplitterFetch extends Thread { TiG?r$6v%
{X_I>)Wg
9HlWoHuC
String sURL; //File URL ~_F;>N~
long nStartPos; //File Snippet Start Position cD)9EFo
long nEndPos; //File Snippet End Position H5 :,hrZY
int nThreadID; //Thread's ID WU@_aw[
boolean bDownOver = false; //Downing is over c5 AaUza
boolean bStop = false; //Stop identical Q"c/]Sk)
FileAccessI fileAccessI = null; //File Access interface \i}-Y[Dg
Aho*E9VW
\DBEs02
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fOdqr
{ }QQ 7jE
this.sURL = sURL; `R7dn/
this.nStartPos = nStart; X?&{< vz
this.nEndPos = nEnd; _6`GHx
nThreadID = id; MA}}w&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >LN*3&W
} ._<, Eodv
+uTl Lu;MT
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public void run() >Bdh`Ot-!
{ Uq{$j5p8
while(nStartPos < nEndPos && !bStop) @#-\BQ;
{ -Lb7=98
i:jB
Dsc0;7~6
try{ njO~^Hl7
URL url = new URL(sURL); G!G:YVWXP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :2/jI:L~
httpConnection.setRequestProperty("User-Agent","NetFox"); .}Ys+d1b9c
String sProperty = "bytes="+nStartPos+"-"; E`hR(UL ?
httpConnection.setRequestProperty("RANGE",sProperty); euRKYGW
Utility.log(sProperty); GRVF/hPn
BSB&zp
qbCU&G|)
InputStream input = httpConnection.getInputStream(); G`Z<a
//logResponseHead(httpConnection); :PY6J}:&#
7zA+UWr
[u^ fy<jdp
byte[] b = new byte[1024]; {.[EXMX
int nRead; G-K{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^;9l3P{
{ =n_z`I
nStartPos += fileAccessI.write(b,0,nRead); ,oSn<$%/q
//if(nThreadID == 1) qN9 ?$\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F7nwVDc*
} }A;YM1^$
F< 5kcu#iL
4<)*a]\c5M
Utility.log("Thread " + nThreadID + " is over!"); S#HeOPRL
bDownOver = true; @'GPZpbvZ
//nPos = fileAccessI.write (b,0,nRead); F?6Q(mRl
} (NDC9Lls
catch(Exception e){e.printStackTrace ();} J4U_utp
} G51-CLM,
} 7/k7V)
/"m#mhL
?z6K/'?
//打印回应的头信息 ja/wI'J<
public void logResponseHead(HttpURLConnection con) 8faT@J'e;
{ $<C",&
for(int i=1;;i++) iQT0%WaHl
{ }~ N\A
String header=con.getHeaderFieldKey(i); Ea'jAIFPpO
if(header!=null) \/gf_R_GN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bb\XZ~)F
Utility.log(header+" : "+con.getHeaderField(header)); .a(G=fk
else }$qrNbLJ
break; skTaIGRL
} r$'.$k\
} ]@Z nP,8
&(l.jgqg&
in,0(I&I
public void splitterStop() )'e1@CR
{ O@W/s!&lFa
bStop = true; ZWzr8oY)
} G(Hr*T%
v.vkQQ0[9
7+@-mJMP$D
} &2[Xu4*
L:mE)Xq2
L;L_$hu)
/* }R5EuR m\
**FileAccess.java wgolgof
*//文件访问(定位，写) r&+C%
package NetFox; 9(}d7y
import java.io.*; IR:{{ (
I@O9bxR?
JC~4B3!
public class FileAccessI implements Serializable{ o"L8n(\
tq@)J_7|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /YU8L
RandomAccessFile oSavedFile; 2Q@Jp`#,4
long nPos; Vm8dX?
"oFi+']*
. .S3-(xW
public FileAccessI() throws IOException ?p 4iXHE
{ V>E7!LIn.
this("",0); c&wiTvRV
} Nge@8
C?]eFKS."
%H&WihQ
public FileAccessI(String sName,long nPos) throws IOException =_g#I
{ ips)-1
oSavedFile = new RandomAccessFile(sName,"rw"); p[At0Gc L
this.nPos = nPos; `'EG7
oSavedFile.seek(nPos); qdKqc,R1{
} 3XQe? 2:<
5 $$Cav
X%JyC_~<
public synchronized int write(byte[] b,int nStart,int nLen) Q8QB{*4
{ vdB2T2F
int n = -1; i^Jw`eAmT
try{ F^%\AA]8
oSavedFile.write(b,nStart,nLen); Fv$w:r]q6
n = nLen; Jg{K!P|i
} Y"KJ`Rx
catch(IOException e) &b*v7c=o
{ ,,80nW9E
e.printStackTrace (); LikCIO
} matm>3n
4x4[
h)j#?\KYm9
return n; f?eq-/UR
} w2/3[VZ}l
v,ni9DIu
O7LJ-M
} -b8SaLak
VYh/URU>
$3&XM
/* XkoPN]0n
**SiteInfoBean.java +t&)Z
*/ Fs=x+8'M
package NetFox; vkR~nIp
{%^4%Eco
!;[cJbqnh
public class SiteInfoBean { |JWYsqJ0U
n c~JAT#'
upZc~k!1\
private String sSiteURL; //Site's URL #*"V'dj;e
private String sFilePath; //Saved File's Path <&O*' <6C
private String sFileName; //Saved File's Name 4^nHq 4_
private int nSplitter; //Count of Splited Downloading File (e!Yu#-
SAf)#HXa
/n>vPJvz
public SiteInfoBean() G973n
{//nSplitter的缺省值为5 *14:^neoI
//default value of nSplitter is 5 -O=xgvh"
this("","","",5); Y$c7uA:4
} @]}/vsI m
_Ye.29
C\Yf]J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -wl&~}%M
{ dV'^K%#
sSiteURL= sURL; eX}aa0
sFilePath = sPath; '/0e!x/8
sFileName = sName; "zTy_0[;
this.nSplitter = nSpiltter; < ]+Mdy
wmXI8'~F&
z-g6d(
} ;1nXJ{jKw
Y9vi&G?Jl
iCh8e>+
public String getSSiteURL() J]S30&?
{ S*J\YcqSC
return sSiteURL; S>*i\OnI'
} o]qwN:8^
~dLbhjden
'|5o(6u'
public void setSSiteURL(String value) 4t/?b
{ r%X M`;bQX
sSiteURL = value; W7_m,{q
} VnB HQ.C
;XjXv'
B^GMncZO
public String getSFilePath() ~Jw84U{$
{ 3K/tB1
return sFilePath; F Qk
} S'ms>ZENC
v+79#qWK|n
W_Hoa*~
public void setSFilePath(String value) ~@X3qja
{ RF'nwzM3
sFilePath = value; hm0A%Js
} I} +up,B]o
YTY(Et1i
jA^Dk$
public String getSFileName() IqsUtWSp
{ S&]r6ss
return sFileName; ;8eGf'
} gVh&c4
xWK/uE(
kz6fU\U
public void setSFileName(String value) 5ZH3}B^L$
{ |42;171
sFileName = value; _29wQn@]
} "XLtrAu{
Yl"CIgt
"zQ<)Q]U
public int getNSplitter() "_dg$j`Y&&
{ $Zw+"AA
return nSplitter; WwtVuc|
} wpi$-i`
P6ktA-Hv>
LayK&RwL
public void setNSplitter(int nCount) 4(oU88z
{ ;~d$OM
nSplitter = nCount; ,RY;dX-#
} c|aX4=Z
} W(4$.uZ)
g.%} +5
s3Zt)xQ3
/* v#<{Y'K
**Utility.java xVX:kDX
*/ ^EkxZ4*g
package NetFox; 5jwv!L<n
bqA`oRb\
VmQ'
public class Utility { `#8kJt
l Ib d9F
!]D`|HoW
public Utility() UQ7]hX9
{ In1n.oRFn^
)s,tBU+N
ST?Rl@4
} +TaxH;
w{2CV\^>5
//线程睡眠 %0/qb0N&
public static void sleep(int nSecond) ^?sP[;8S!
{ v'Ehr**]+
try{ 6~2upy~e
Thread.sleep(nSecond); *mJ#|3I<
} =_N[mR^
catch(Exception e) qnWM %k
{ CxJ3u
e.printStackTrace (); w{k^O7~
} JsuI&v
} +Ss3Ph
/BQqg08@L
//日志 3#dz6+
public static void log(String sMsg) uPr!;'J=
{ fsw[R0B
System.err.println(sMsg); \f(zMP
} E"S#d&9
Z2})n -
[XDV-6KCE.
public static void log(int sMsg) ">3t+A
{ 1i~q~O,
System.err.println(sMsg); G7v<Q,s
} D|m3.si
} _kMHF
j3`YaWw
hi/d%lNZ
/* MMpId Uhr
**TestMethod.java '7oCWHq[
*/ _&9P&Zf4
package NetFox; [TUs^%2@
<;?1#ok
#Y=b7|l
public class TestMethod { z~~pH9=c2
&p_iAMn:9
n^l*oEl
public TestMethod() 6m(? (6+;K
{ ///xx/weblogic60b2_win.exe _,aFQ^]'9
try{ P!IA;i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,Zb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uYg Q?*Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4 ?PB Fbd
fileFetch.start(); 4;AQ12<[1
} (?^F }]
catch(Exception e){e.printStackTrace ();} ^p9V5o
\<T7EV.
H?Q--pG8
} hE`d@
x7<l*WQ
fKr_u<|
public static void main(String[] args) v^s?=9
{ 0|j44e}
new TestMethod(); ~1}fL 1~5
} j$/#2%OVN
} $t}W,?
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