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)); ~ao:9ynY
} YQBLbtn6(
for(int i=0;i<nEndPos.length-1;i++) >3 o4 U2
{ 6(n0{A
nEndPos = nStartPos[i+1]; djd/QAfSC
} )U/jD
nEndPos[nEndPos.length-1] = nFileLength; VYk:c`E
} fvu{(Tb
} ]Q^)9uE\D
!/FRL<mp
\J'}CX*aQ
//启动子线程 M0V<Ay\%O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TW|K.t@5#H
for(int i=0;i<nStartPos.length;i++) VkQ@c;C
{ kAftW '
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $8tk|uh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D"7}&Ry:
nStartPos,nEndPos,i); 55Ss%$k@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qZ1'uln=C-
fileSplitterFetch.start(); )6"}M;v
} K-RmB4WI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RD$:.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %OQdUH4x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2W AeSUX
nEndPos = " + nFileLength); .-gJS-.c
// fileSplitterFetch[nPos.length-1].start(); D,#UJPyg
#{i*9'
waMF~#PJlt
//等待子线程结束 WAu>p3
//int count = 0; NxP(&M(
//是否结束while循环 Kz HYh
boolean breakWhile = false; lC<;Q*Y
a4Q@sn;]
}(EH5jZ'
while(!bStop) !fOPYgAGKn
{ epy2}TI
write_nPos(); zsL@0]e&
Utility.sleep(500); 9+ 'i(q z
breakWhile = true; rXx#<7`
-TUJ"ep]QJ
6VW*8~~Xy
for(int i=0;i<nStartPos.length;i++) ZW4f "
{ XKp&GE@Y
if(!fileSplitterFetch.bDownOver) 8^7Oc,:~
{ I)rnF
breakWhile = false; qng ~,m
break; a5*r1,
} ImXYI7PL
} \&"C
if(breakWhile) \xYVnjG,
break; 4Aj~mA
dNACE*g;q
lF}[ YL
//count++; >pq~ &)^u
//if(count>4) @16GF!.
// siteStop(); p9v:T1?
} 7=-Yxt
d$!Q6ux;
g=Xf&}&=x
System.err.println("文件下载结束！"); ?sN{U\
} DDE-$)lf>
catch(Exception e){e.printStackTrace ();} %>+uEjbT
} X[BP0:`t
kR=sr/{
!%>RHh[
//获得文件长度 {_9O4 + &
public long getFileSize() =?5)M_6)
{ BgQEd@cN
int nFileLength = -1; k:0j;\Sx
try{ ;1k&}v&
URL url = new URL(siteInfoBean.getSSiteURL()); E&U_1D9=L<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z?)g'n
httpConnection.setRequestProperty("User-Agent","NetFox"); 7;jD>wp9D
"O34 E?ql.
6bm7^e(
int responseCode=httpConnection.getResponseCode(); ,#Z%0NLe
if(responseCode>=400) ;;0'BdsL`
{ |UTajEL
processErrorCode(responseCode); {npm9w<;
return -2; //-2 represent access is error :=Olp;+_
} 2`o @L
B+W7zv
v[dUUR f
String sHeader; xf,[F8 2y
]?^V xB7L
adLL7
for(int i=1;;i++) z33UER"
{ nCQtn%j't
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =%<=Bn
//Utility.log(in.readLine()); hGtz[u#p
sHeader=httpConnection.getHeaderFieldKey(i); l5 9a3=q
if(sHeader!=null) Pn,I^Ej.
{ M(X _I`\E
if(sHeader.equals("Content-Length")) wQ33Gc
{ )qy?x7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bP18w0>,
break; 2KLMFI.F
} ibkB>n{(
} @KQ>DBWQM
else EI_-5TtRD
break; >wW{$
} mnm ZO}
} ]Lv3XMa
catch(IOException e){e.printStackTrace ();} wJC[[_"3 I
catch(Exception e){e.printStackTrace ();} L FWp}#%
lV\iYX2#
1K Vit{
Utility.log(nFileLength); JduO^Fit
2Q6;SF"Z
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return nFileLength; K(;qdIr
} ,rMf;/[
sVHF\{<
P< OH{l
//保存下载信息（文件指针位置） ,,Qg"C
private void write_nPos() s= %3`3Fo
{ #^}H)>jWy
try{ oU\]#e^
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rqe.=+Qs
output.writeInt(nStartPos.length); nxZz{&
for(int i=0;i<nStartPos.length;i++) C19N0=
{ Pe<VPf9+
// output.writeLong(nPos); 8~Kq"wrbu
output.writeLong(fileSplitterFetch.nStartPos); e,%|sAs[
output.writeLong(fileSplitterFetch.nEndPos); DNGyEC
} O#)1zD}
output.close(); AjK5x@\
} KA2>[x2
catch(IOException e){e.printStackTrace ();} 8pnD6Lp>
catch(Exception e){e.printStackTrace ();} 5,Fq:j)MxW
} Skr(C5T
r#zcl)rbU
OxHcoNrz
//读取保存的下载信息（文件指针位置） ;\K]~
private void read_nPos() $;^|]/-
{ $Cz2b/O
try{ s#^0[ Rt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ul8HWk[6Iw
int nCount = input.readInt(); m.lR]!Y=w
nStartPos = new long[nCount]; ;W- A2g
nEndPos = new long[nCount]; 2 7)IfE
for(int i=0;i<nStartPos.length;i++) gmVN(K}SR5
{ \Oq2{Sx\
nStartPos = input.readLong(); }O\IF}X
nEndPos = input.readLong(); i:s=
} M-@RgWvF
input.close(); JwI99I'
} 2Qe&FeT
catch(IOException e){e.printStackTrace ();} o;@~uU
catch(Exception e){e.printStackTrace ();} L3b0e_8>R
} <|r|s
}u8(7
Ta\F~$M
private void processErrorCode(int nErrorCode) J _rrc;F
{ R+HX'W
System.err.println("Error Code : " + nErrorCode); }H ~-oYMu
} KElEGW
{Z2nc)|7C
CcQc!`YC
//停止文件下载 F\eQV<
public void siteStop() 5aaM;45C
{ +jhzE%
bStop = true; Ar<5UnT
for(int i=0;i<nStartPos.length;i++) L6h<B :l
fileSplitterFetch.splitterStop(); g+B7~Z5,
_y4O2n[e
F0!Z1S0g
} ei-\t qY_
} (_ G>dP_
//负责部分文件的抓取 |OeWM
**FileSplitterFetch.java [q|W*[B:@
*/ ,sitOy}ks
package NetFox; o< @![P
rd7p$e=i
ao)';[%9s
import java.io.*; 35l%iaj]G5
import java.net.*; BL&AZv/T
]W;6gmV
`df!-\#
public class FileSplitterFetch extends Thread { O50_qu33ju
~u&gU1}
7"!`<5o^
String sURL; //File URL 7<su8*?
long nStartPos; //File Snippet Start Position SnG(/1C8
long nEndPos; //File Snippet End Position +&S7l%-
int nThreadID; //Thread's ID @ujwN([I
boolean bDownOver = false; //Downing is over K 4GuOl
boolean bStop = false; //Stop identical o8X_uKEI
FileAccessI fileAccessI = null; //File Access interface _0+X32HjJ
GST#b6S
/0}Z>iK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x=cucZ
{ i D9 */
this.sURL = sURL; U~D~C~\2;
this.nStartPos = nStart; 0B(s+#s
this.nEndPos = nEnd; <&m50pq
nThreadID = id; jfG of*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {wC*61@1
} G4'Ia$
pa46,q&M
x`g,>>&C
public void run() $z[S0Cm
{ Z3JUYEAS
while(nStartPos < nEndPos && !bStop) JuSS(dJw
{ v#x`c_
<8}FsRr;J
eN<L)a:J_
try{ + ,Krq 3P
URL url = new URL(sURL); l/={aF7+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D^4nT,&8
httpConnection.setRequestProperty("User-Agent","NetFox"); WO.u{vW]'
String sProperty = "bytes="+nStartPos+"-"; VgVDTWs7
httpConnection.setRequestProperty("RANGE",sProperty); Qa,=
Utility.log(sProperty); TVcA%]y{;
E!ndXz 59
7?yS>(VmT
InputStream input = httpConnection.getInputStream(); 9)7$UQY
//logResponseHead(httpConnection); AJ%E.+@=r
YVccO~!8
!~|-CF0z=
byte[] b = new byte[1024]; TR3U<:
int nRead; a U\|ZCH\]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &jqylX
{ PcC@}3
nStartPos += fileAccessI.write(b,0,nRead); ?JZ$M
//if(nThreadID == 1) >eA@s}_8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e@vtJaSu
} ]mMJ6n
9:p-F+
Aax;0qGbH
Utility.log("Thread " + nThreadID + " is over!"); l~"T>=jq3
bDownOver = true; KAnV%j
//nPos = fileAccessI.write (b,0,nRead); jh/,G5RM9
} BP9#}{kE
catch(Exception e){e.printStackTrace ();} YH\9Je%jx
} ~yJ2@2I
} qt}M&=}8Q
(=^KP7
&Pb:P?I
//打印回应的头信息 bg Ux&3
public void logResponseHead(HttpURLConnection con) $.vm n,:.
{ 3q73L<f
for(int i=1;;i++) *|S6iSn9R!
{ {R ),7U8
String header=con.getHeaderFieldKey(i); o*)Sg6Yk
if(header!=null) ynmjIQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); - ]wT
Utility.log(header+" : "+con.getHeaderField(header)); p?f\/
else bVzi^R"
break; }O*`I(
} @?<[//1
} T)gulP
KFbB}oId
3'.@aMA@
public void splitterStop() bVUIeX'
{ *:yG)J 3F
bStop = true; k^Qf |
} N#l2wT
?)1Y|W'Rv
ol"|?*3q
} kY$EK]s
I Id4w~|
XY| y1L 3[
/* 44}5o
**FileAccess.java f7a4E+}
*//文件访问(定位，写) &1Ndi<Y^
package NetFox; _94 W@dW
import java.io.*; ??"_o3
YHEn{z7
U|3!ixk>>w
public class FileAccessI implements Serializable{ Nhs!_-_I
dLp1l2h!0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tfU*U>j
RandomAccessFile oSavedFile; o=YOn&@%
long nPos; M?lh1Yu"
}R}+8
U=bx30brh%
public FileAccessI() throws IOException >SI'Q7k
{ M,fL(b;2
this("",0); n.+'9Fj
} wS}c\!@<,
LH4A!a]
:$"{-n
public FileAccessI(String sName,long nPos) throws IOException W q<t+E[
{ lndz
oSavedFile = new RandomAccessFile(sName,"rw"); &q>8D'
this.nPos = nPos; e\C-a4[C8P
oSavedFile.seek(nPos); dQ8RrD=$&
} U:TkO=/>:
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Qx4)'n
public synchronized int write(byte[] b,int nStart,int nLen) zz*PAYl.
{ [8Pt$5]^
int n = -1; :dt[ #
try{ _<c"/B
oSavedFile.write(b,nStart,nLen); ARu_S B
n = nLen; s-IE}I?;
} ts~VO`
catch(IOException e) {\(G^B*\
{ C*2%Ix18+N
e.printStackTrace (); fi HE`]0
} 2?~nA2+vm
!}!KT(%%
:C_/K(Rkl
return n; (C. $w
} 1(Is 7
m~&
<'4Wne.z!
} D;!sH?J@+
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dq '2y
/* c6[m'cy
**SiteInfoBean.java >B{qPrmI
*/ ]pvHsiI:
package NetFox; MZz9R*_VS
Rmw=~NP5
]Uwp\2Bc
public class SiteInfoBean { "IU}>y>J
lBfthLBa
\na$Sb+
private String sSiteURL; //Site's URL uJ2ZHrJ
private String sFilePath; //Saved File's Path H7'42J@
private String sFileName; //Saved File's Name QDn_`c
private int nSplitter; //Count of Splited Downloading File r4mh:T4i
Sl8+A+
~ =u8H
public SiteInfoBean() 4;L|Ua
{//nSplitter的缺省值为5 Z+k) N
//default value of nSplitter is 5 hA ){>B<;
this("","","",5); o:#jvi84F
} eF%M2:&c;
''9]`B,:a0
0HWSdf|w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a Y)vi$;]
{ %d+Fq=<
sSiteURL= sURL; ^dpM2$J
sFilePath = sPath; w<B S
sFileName = sName; 'aEK{#en
this.nSplitter = nSpiltter; TIJH}Ri
$}(Z]z}O;
:Hq%y/
} ^P9mJ:
V<9L-7X 8
p-"C^=l
public String getSSiteURL() Qp<*or@
{ "9xJ},:-
return sSiteURL; ?>+uO0*S
} ={xRNNUj_
)r.Wge
m^oG9&";
public void setSSiteURL(String value) LhAN( [
{ 1vq2`lWpx
sSiteURL = value; 9C \}bT
} vT#R>0@mi
q%G[tXw
B5 /8LEWw
public String getSFilePath() "1gIR^S%9
{ Y!j/,FU
return sFilePath; ^!B]V>L-
} diNSF-wi,,
gN}$$vS
p|gVIsg[-e
public void setSFilePath(String value) C1{Q 4(K%
{ "S#$:92
sFilePath = value; [,Ul
} K-]) RIM
<p<6!tdO
#om Gj&
public String getSFileName() M%:\ry4:
{ yreH/$Ou8
return sFileName; 0 @#Jz#?
} oPs asa
=EVB?k ,
aO$0[-A
public void setSFileName(String value) EJ {vJZO
{ pImq<Z
sFileName = value; U`) ";WN
} <q'?[aKvR
zr ez*
Srw`vql{(
public int getNSplitter() "d-vs t5
{ 5dv|NLl
return nSplitter; 1;m?:|6K{
} AM?ZhM
lFuW8G,-f@
k@fxs]Y_L
public void setNSplitter(int nCount) )r"R
{ Z<|x6%
nSplitter = nCount; B[mZQ&Gz`a
} @8\0@[]
} v3[ZPc;;
Ew]&~:$Ki
LntRLB'
/* +mG"m hF
**Utility.java T=w0T-[f
*/ j7);N
package NetFox; [|$C2Dhw=
GF@`~im
ug}u>vQ>
public class Utility { IHW s<U
[6K[P3UZx
4NRj>y
public Utility() E @r &K
{ Lwtp,.)pR
I5j|\ /Ht
R{H8@JLD
} "uZ^zV`"
]hlQU%&
//线程睡眠 xTG5VBv
public static void sleep(int nSecond) S9*68l
{ 0{d)f1
try{ fvta<
Thread.sleep(nSecond); ?pQ0* O0
} zBca$Vp
catch(Exception e) l^tRy_T:-
{ k0FAI0~(
e.printStackTrace (); 0f_`;{
} Q-iBK*-w
} - ]/=WAOK
`}ZtK574
//日志 ?Z!R
public static void log(String sMsg) "KCG']DF
{ 3it*l-i\
System.err.println(sMsg); kg(}%Ih
} asQ^33g z
modem6#x'
cAx$W6S
public static void log(int sMsg) ,ZYPffu<*
{ }]1C=~lC
System.err.println(sMsg); `)8SIx
} |BtFT
} jc32s}/H
LGtw4'yr
)`<&~>qp
/* `p)U6J
**TestMethod.java butBS
*/ -oZw+ge}
package NetFox; T#e|{ZCbq
N3Q .4? z9
Z>/ *q2
public class TestMethod { CZ^ ,bad
]"O*&
u!HbS*jqq
public TestMethod() Ke[`zui@?
{ ///xx/weblogic60b2_win.exe h0x'QiCc
try{ Jz0AYiCq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _/ 5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $WRRCB/A6
SiteFileFetch fileFetch = new SiteFileFetch(bean); %b h:c5
fileFetch.start(); <Pf4[q&wM
} L*rCUv`
catch(Exception e){e.printStackTrace ();} [Tvdchl OC
ES(qu]CjI
6h) &h1Yd
} K4RQ{fWpm
00>knCe6
klc$n07
public static void main(String[] args) L[5U(`q[
{ benqm ~{\
new TestMethod(); b!/-9{
} %ol1WG9
} Y~r)WV!G
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