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)); 6!se,SCvw
} (((|vI3 <
for(int i=0;i<nEndPos.length-1;i++) =ea.+
{ uvAJJIae'
nEndPos = nStartPos[i+1]; DkSs^ym
} uu.}<VM.1
nEndPos[nEndPos.length-1] = nFileLength; ?G<ISiABQC
} sDY+J(Z
} u@;e`-@
z+{xW7
y\})C-&
//启动子线程 gT(8.<h8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Jf}3$Ra
for(int i=0;i<nStartPos.length;i++) 1aZGt2;
{ <I#M^}`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +`iJ+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ((&5F!+\-
nStartPos,nEndPos,i); 1Ko4O)L]&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &WeN{
fileSplitterFetch.start(); ROXa/
} ~uV(/?o%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1IlOU|4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PuhvJHT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z6-ZAS(>m
nEndPos = " + nFileLength); M!D6i5k,
// fileSplitterFetch[nPos.length-1].start(); gWL`J=DiU
vOLa.%X]h
5,4m_fBoW
//等待子线程结束 {9@u:(<X9
//int count = 0; <xe_t=N
//是否结束while循环 Cg|\UKfy$
boolean breakWhile = false; LIrebz
06M?ecN
|MOz>1<a
while(!bStop) ddN G:
{ :>/6:c?atG
write_nPos(); CYlS8j
Utility.sleep(500); LJom+PxF$x
breakWhile = true; f-634KuP
>FKwFwT4D
80`$F{xcX
for(int i=0;i<nStartPos.length;i++) /\;m/cwrl"
{ 'c_K[p$
if(!fileSplitterFetch.bDownOver) l|{[vZpT
{ nW} s
breakWhile = false; xQ2:tY#?
break; )Ay90Wt
} <s7cCpUFP
} &r,)4q+
if(breakWhile) g~$UU(HX
break; |fIyq}{7
f$tm<:)Y
T:Ovh.$
//count++; mYj)![
//if(count>4) GwfCl{l
// siteStop(); +KD7Di91<K
} ;4(}e{
x7Gf):,LK
j@w1S[vt
System.err.println("文件下载结束！"); :`Ep#[Wvo
} Br15S};Ce
catch(Exception e){e.printStackTrace ();} z{FFTb^B
} o(H.1ESk
Vh>cV
=R~zD4{"
//获得文件长度 2gZ nrU
public long getFileSize() HTv#2WX
{ #0hqfs
int nFileLength = -1; qE|syA9
try{ .ANR|G
URL url = new URL(siteInfoBean.getSSiteURL()); QQ_7Q^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2P)O 0j\/
httpConnection.setRequestProperty("User-Agent","NetFox"); 1q@R04i
4P"bOt5izR
kN78j
int responseCode=httpConnection.getResponseCode(); f0j]!g
if(responseCode>=400) "*.N'J\
{ GmaNi
processErrorCode(responseCode); lGBg8/[
return -2; //-2 represent access is error Lr5{c5M
} <,rOsE6
y4LUC;[n
ggiy{CdR
String sHeader; <9piKtb|L
lSW'qgh
f$6N
for(int i=1;;i++) h6OQeZ.
{ zA8@'`Id
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wpN3-D
//Utility.log(in.readLine()); d6ef)mw
sHeader=httpConnection.getHeaderFieldKey(i); vV*J;%MO
if(sHeader!=null) fU?#^Lg
{ Lt=32SvTn
if(sHeader.equals("Content-Length")) \/?J)k3H.
{ Rw%?@X3m]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l_yF;5|?z
break; u '/)l}
} Nh_\{ &r
} aK95&Jyw&
else hc+B+-,
break; N%xCyZ
} ,ofE*Wt
} -egnMc67
catch(IOException e){e.printStackTrace ();} DyCzRkH
catch(Exception e){e.printStackTrace ();} e,VF;Br
,z>-_HOnw
86N,04
Utility.log(nFileLength); fZ5 UFq_~s
83SK<V6
IQ~qiFCf
return nFileLength; }8#Ed;%K
} bT&{8a
u~j H
R:YVmqd
//保存下载信息（文件指针位置） %),u0:go
private void write_nPos() ;nP(S`'
{ 5cinI^x)f
try{ :;yrYAyT3
output = new DataOutputStream(new FileOutputStream(tmpFile)); }O>1tauI
output.writeInt(nStartPos.length); j&_>_*.y
for(int i=0;i<nStartPos.length;i++) }`Ya;
{ 7/51_=%kR
// output.writeLong(nPos); P1T{5u!T
output.writeLong(fileSplitterFetch.nStartPos); pR93T+X
output.writeLong(fileSplitterFetch.nEndPos); NWvIwt{
} _<FUS'"
output.close(); h=gtuaR4
} Wp8>Gfb2
catch(IOException e){e.printStackTrace ();} "q+Z*
catch(Exception e){e.printStackTrace ();} c8"Qmy
} #gO[di0WhC
c/A?-9
05T?c{ ;
//读取保存的下载信息（文件指针位置） q,@# cQBV
private void read_nPos() W/xPVmnV
{ 6bhb_U'f
try{ CvE^t#Bok
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *c[w9(fU
int nCount = input.readInt(); 8|=C/k
nStartPos = new long[nCount]; (w)%2vZ^
nEndPos = new long[nCount]; yzp#
for(int i=0;i<nStartPos.length;i++) x@Z{5w_a
{ #f24a?n|
nStartPos = input.readLong(); v$Fz^<Na
nEndPos = input.readLong(); T`fT[BaY
} #jg-q|nd
input.close(); ,^8':X"A{!
} `1(ED= |
catch(IOException e){e.printStackTrace ();} `|?<KF164
catch(Exception e){e.printStackTrace ();} <I34@;R c
} [B;okW
W j^@Zq#
/~w*)e)
private void processErrorCode(int nErrorCode) QrK%DN
{ B os`+Y
System.err.println("Error Code : " + nErrorCode); CU\gx*=E
} {%u^O/M
`x/i1^/_@
ah,f~.X_|
//停止文件下载 'Xj^cX
public void siteStop() d=qVIpZ
{ PHqg~q;*
bStop = true; /qy6YF8;y
for(int i=0;i<nStartPos.length;i++) m\XsU?SuX
fileSplitterFetch.splitterStop(); !>> A@3
%K|f,w=m
$.4A?,d
} RVttk )Ny
} TG$#aX\'
//负责部分文件的抓取 >"bW'
**FileSplitterFetch.java iSezrN
*/ d;YKw1
package NetFox; Slg*[r#
n({%|O<|
F<g&t|@
import java.io.*; 6c-3+,Y"#
import java.net.*; ?[zw5fUDS
AF"7 _
6_KvS
public class FileSplitterFetch extends Thread { {:!>Y1w>
gR# k'
l1k&@1"
String sURL; //File URL tUxH6IS
long nStartPos; //File Snippet Start Position 9gw;MFP)D
long nEndPos; //File Snippet End Position z+Fu{<#(
int nThreadID; //Thread's ID eZ(ThA*2=t
boolean bDownOver = false; //Downing is over Gm:s;w-;v
boolean bStop = false; //Stop identical %6uZb sa
FileAccessI fileAccessI = null; //File Access interface 4vWiOcJF!O
SkmTW@v
CYy=f-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -_t4A *
{ XJeWhk3R9
this.sURL = sURL; ptT-{vG
this.nStartPos = nStart; :Q("
this.nEndPos = nEnd; Ue9Y+'-x
nThreadID = id; iKrk?B<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2H.g!( Oza
} /}~=)QHH
7yyX8p>
3W[?D8yi)
public void run() D tZ?sG
{ a)pc+w#
while(nStartPos < nEndPos && !bStop) mbkt7. ,P
{ a($7J6]M
KF+r25uy[+
aUEr& $
try{ AH&RabH2
URL url = new URL(sURL); uthW AT &
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r+C4<-dT
httpConnection.setRequestProperty("User-Agent","NetFox"); z8t;jw
String sProperty = "bytes="+nStartPos+"-"; Fnak:R0
httpConnection.setRequestProperty("RANGE",sProperty); Ez|NQ:o
Utility.log(sProperty); 3JQ7Cc>
xtP:Q9!N
d%0Gsga}
InputStream input = httpConnection.getInputStream(); vO2WZ7E!
//logResponseHead(httpConnection); H%Gz"
G$TO'Ciu:
Xrb7.Y0d
byte[] b = new byte[1024]; ?{"r(
int nRead; ^PNDxtd|v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k5aB|xo
{ ]>(pj9)
nStartPos += fileAccessI.write(b,0,nRead); J";N^OR{A%
//if(nThreadID == 1) hQj@D\}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Gl'G;F$Y-
} W/BPf{U
;]grbqXVE
:5CyR3P
Utility.log("Thread " + nThreadID + " is over!"); o-H?q!
bDownOver = true; v%T'!(0j/
//nPos = fileAccessI.write (b,0,nRead); q{9 \hEeb
} $?W2'Xm!V
catch(Exception e){e.printStackTrace ();} EB!ne)X
} nX3?7"v
} ?lD)J?j
`OMX 9i
b;jdk w|
//打印回应的头信息 $k0(iFzR1
public void logResponseHead(HttpURLConnection con) H;\C7w|
{ q,)V0Ffe[|
for(int i=1;;i++) K\9CW%W
{ E} XmZxHV
String header=con.getHeaderFieldKey(i); 0ex.~S_Oj4
if(header!=null) J78.-J5 j0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vwu/33
Utility.log(header+" : "+con.getHeaderField(header)); Wj,s/Yr:
else R&Nl!QTJj
break; H@@ 4n%MK
} asYk#;z\"
} ~;CNWJtcf(
\ZADY.ha
q&z'S
public void splitterStop() oB5\^V$
{ F|> 3gW
bStop = true; G!$~'o%/
} 3ArHaAv{y
_N|%i J5
A{q%sp:3~
} ,on]Fts
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Z qn$>mG-
/* 7P3pjgh
**FileAccess.java @U=y}vi8
*//文件访问(定位，写) %r1#G.2YW
package NetFox; &,G2<2_b
import java.io.*; ZH\t0YhrVe
(4 ZeyG@
b3-j2`#
public class FileAccessI implements Serializable{ +7w5m
rZdOU?U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 })^eaLBR4
RandomAccessFile oSavedFile; 5]I)qij q
long nPos; ' F.^ 8/>
;=0mL,
W;I{4ed6
public FileAccessI() throws IOException F_:zR,P%#
{ X,VI5$
this("",0); nm#23@uZ4K
} WRu(F54Sk
9R8q+2
0,RYO :`
public FileAccessI(String sName,long nPos) throws IOException 5@>hjXi"Y
{ ?[ )}N _o#
oSavedFile = new RandomAccessFile(sName,"rw"); r]cq|Nv8:
this.nPos = nPos; hOk9y=
oSavedFile.seek(nPos); ,e'm@d$Q*
} z[J=WI
rd0Fd+t/
vVo'f|fW
public synchronized int write(byte[] b,int nStart,int nLen) 3?V'O6
{ G@ot^n3
int n = -1; trrNu
try{ .q MxShUU
oSavedFile.write(b,nStart,nLen); &j:prc[W
n = nLen; 'e]>lRZ
} 8[J%TWq%9
catch(IOException e) cy,6^d
{ n(Nu
e.printStackTrace (); :1qLRr
} K!CVS7
?1\I/'E9
#Q7:Mu+
return n; q-Z<.GTq
} 8m' f8.x
1(Vv-bq$
I= :yfW
} wX)'1H):T
zNo,PERG
V.`hk^V,
/* J&\Q3_vro9
**SiteInfoBean.java \wz^Z{U
*/ IQ\!wWKmY
package NetFox; ^}$t(t
>4wigc
iWjNK"W
public class SiteInfoBean { 'Iw`+=iVz
>mA]2gV<a
Y<W9LF
private String sSiteURL; //Site's URL Bv~^keuj3t
private String sFilePath; //Saved File's Path ,X_3#!y
private String sFileName; //Saved File's Name &cyB}Gv
private int nSplitter; //Count of Splited Downloading File 16Ka>=G
Fu{VO~w
geK;r0(f
public SiteInfoBean() !%R):^R8
{//nSplitter的缺省值为5 Ld_uMe?Z
//default value of nSplitter is 5 %_:L_VD@
this("","","",5); 19GF%+L ,
} <$?#P#A
sT1OAK\^
83vZRQw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .CEC g*f
{ I_f%%N%
sSiteURL= sURL; Zex~ $r
sFilePath = sPath; g0biw?
sFileName = sName; fsOlg9
this.nSplitter = nSpiltter; dl=)\mSFjF
fIpS P@$<
/'{vDxZf R
} <fBJ@>
tBzE(vW
[K #$W
public String getSSiteURL() XO?WxL9k]
{ L>/$l(
return sSiteURL; zZ-/S~l
} g~21|Sa$[
/xgC`]-
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public void setSSiteURL(String value) phb ;D
{ )OQm,5F1
sSiteURL = value; Oi|cTZ@A-
} 5w>TCx
V$DB4YM1k
Yf[Cmn
public String getSFilePath() $G0e1)D
{ %9zpPrWF
return sFilePath; DmgDhNXKq
} lv]U)p
.=}\yYGe
{@Lun6\
public void setSFilePath(String value) +~F>:v?Rh
{ #"A`:bjG
sFilePath = value; 5);"()g32
} .mrv"k\<
iDDq<a.A
>j]Gz-wC
public String getSFileName() tC1'IE-h
{ %Jl6e}!
return sFileName; >N! Xey
} E5S(1Z}]p{
T)22P<M8
FB?V<x
public void setSFileName(String value) uh9b!8
{ V 7~9z\lW
sFileName = value; z I9jxwXU
} ysp,:)-%G@
=1>G* ,
c9H6\&
public int getNSplitter() 7C2Xy>d~
{ |;V-;e*
return nSplitter; ,>(X}Q
} zuMz6#aCC8
`TF3Ho\MC
-[>J"l
public void setNSplitter(int nCount) sDgo G
{ .yTo)t
nSplitter = nCount; 3k6Dbz
} ZiKO|U@/
} uHf1b?W
.I{u[ "
K ..Pn17t
/* DZESvIES
**Utility.java ffB<qf)?G
*/ Z 5 .cfI[
package NetFox; , =*^XlO=c
kN<;*jHV
,lCFe0>k!=
public class Utility { b-`P-
Y -BZV |
KIuj;|!q
public Utility() U\{I09@E 0
{ _^eA1}3
~PpU'[
&j'k9C2p
} 4u2_xbT
k_^ 4NU
//线程睡眠 ='Oxy
public static void sleep(int nSecond) g-x;a0MQx
{ e7Gb7c~
try{ <#Fex'4
Thread.sleep(nSecond); mT j
} lzFg(Ds!f
catch(Exception e) HF&dHD2f
{ G'HLnx}Yi
e.printStackTrace (); (7~vOWs:[
} Iw$T'I+4W
} rw@N=`4P
"$"<AKCwS
//日志 ^^xzaF
public static void log(String sMsg) g*9&3ov
{ )i-`AJK-'v
System.err.println(sMsg); YSZ[~?+
} oqK: 5|
``Um$i~e%
Ex}TDmTu
public static void log(int sMsg) H0Sm4
{ 3WfZzb+
System.err.println(sMsg); Y8mv[+Z
} >qI:
} ZkMHy1
Np~qtR
h^K>(x
/* m|Z[8Tup
**TestMethod.java i-k(/Y0
*/ 7` XECIh
package NetFox; </fTn_{2s8
<PO-S\N
1-!|_<EW1
public class TestMethod { kl&_O8E+K
iIo>]\Pw
9FT==>
public TestMethod() 3fop.%(
{ ///xx/weblogic60b2_win.exe b` 9Zin
try{ Ki)hr%UFw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \\"CgH-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .= 8Es#
SiteFileFetch fileFetch = new SiteFileFetch(bean); !\&4,l(
fileFetch.start(); H/G;hk
} 3bugVJ93
catch(Exception e){e.printStackTrace ();} )4+uM'2%
J2`OJsMwWe
O_SM!!,
} 6& 9q6IIy
?N%5c%oF
mvtuV`
public static void main(String[] args) }4>#s$.2
{ URTJA<r8D
new TestMethod(); 61TL]S8
} S7hfwu&7F
} ! }awlv;
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