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)); Z<6XB{Nh\
} [m3[plwe
for(int i=0;i<nEndPos.length-1;i++) 1'wwwxe7
{ u-g2*(ZT
nEndPos = nStartPos[i+1]; O`_!G`E
} zWYm*c"n\
nEndPos[nEndPos.length-1] = nFileLength; e"9u}-Q@
} jEwfa_Q%
} zi7,?bD
al<[iZ
6KuB<od
//启动子线程 4<b=;8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,;LxFS5\
for(int i=0;i<nStartPos.length;i++) t .*z)N
{ B@Acm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z DDvXz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 42X N*br
nStartPos,nEndPos,i); ;Z%PBMa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \~|+*^e)
fileSplitterFetch.start(); R0dIxG%
} q 65mR!)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UV}\#86!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UX3 ]cr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {[~cQgCI
nEndPos = " + nFileLength); 0F$;]zg
// fileSplitterFetch[nPos.length-1].start(); dc[w`
(\^| @
H4[];&]xr
//等待子线程结束 DK8eFyG^2
//int count = 0; <BoDLvW>
//是否结束while循环 Y)*5M
boolean breakWhile = false; W`HO Q
oG5:]/F
Ig9yd S-.
while(!bStop) ]B'Ac%Rx
{ 88\0opL-
write_nPos(); jb~2f2vUa
Utility.sleep(500); sHC4iMIw
breakWhile = true; X2>qx^jT
?;1^8 c0
t?JY@hT*
for(int i=0;i<nStartPos.length;i++) bvZTB<rA
{ KLqn`m`O;
if(!fileSplitterFetch.bDownOver) 6q^Tq {I
{ ].Mr&@
breakWhile = false; @]$qJFXx
break; "vVL52HwB
} :2#8\7IU^'
} MRzrZZ%LQ
if(breakWhile) .I%p0ds1r
break; sU>!sxW
)Ih'0>=
LwDm(gG
//count++; &w@~@]
//if(count>4) fAMJFHW
// siteStop(); axT-
} r,^}/<*
H]v"_!(\
(ATvH_Z
System.err.println("文件下载结束！"); Y@WCp
} ?U~}uG^
catch(Exception e){e.printStackTrace ();} q}Wd`>VDR
} QIl![%
'^Kmfc
" jefB6k9h
//获得文件长度 -cW`qWbd
public long getFileSize() xsjJ8>G
{ .O9A[s<
int nFileLength = -1; 2K/+6t}
try{ pyPS5vWG
URL url = new URL(siteInfoBean.getSSiteURL()); Of|e]GR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); = ~{n-rMF
httpConnection.setRequestProperty("User-Agent","NetFox"); Sb_T _m
nv WTx4oy
yP:/F|E$
int responseCode=httpConnection.getResponseCode(); 9d ZE#l!Q
if(responseCode>=400) slSQ\;CDA
{ Qg]8~^Q<
processErrorCode(responseCode); nsChNwPX
return -2; //-2 represent access is error W)rE_tw,|
} z0ULB?*"
u+7B-l=u*
YLc 2:9
String sHeader; `V N $ S
EA )28]Y.
_H#l&bL@C
for(int i=1;;i++) )u{)"m`&[J
{ <.c@l,[.z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JDO5eEwj
//Utility.log(in.readLine()); v]*(Wd~|
sHeader=httpConnection.getHeaderFieldKey(i); FS.z lk\D=
if(sHeader!=null) "zJGYBen
{ =}@m$g
if(sHeader.equals("Content-Length")) F12tOSfu*
{ xW84g08_,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TF %8pIg>Z
break; :UuPy|>
} B Z:H$v
} @&f3zq
else "z+Z8l1.
break; S30@|@fTz
} H*U\P2C!)
} !X 3/2KRP7
catch(IOException e){e.printStackTrace ();} p^_E7k<ag
catch(Exception e){e.printStackTrace ();} [oOA@
#A|~s;s>N
.hh2II
Utility.log(nFileLength); Up|\&2_
ZB-+bY
.F'fBT`$
return nFileLength; (n{sp
} -e_+x'uF
5[WhjTo
{Kp<T
//保存下载信息（文件指针位置） PPCZT3c=
private void write_nPos() Uk5O9D0 He
{ 5- Q`v/w;
try{ H!dUQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); MxiU-
output.writeInt(nStartPos.length); ailje
for(int i=0;i<nStartPos.length;i++) dvUBuY^[
{ K`PmWxNPh
// output.writeLong(nPos); V'h O
output.writeLong(fileSplitterFetch.nStartPos); 7#Qa/[? D
output.writeLong(fileSplitterFetch.nEndPos); -C$Z%I7 0
} /*GRE#7S
output.close(); cK.T=7T
} md[FtcY\
catch(IOException e){e.printStackTrace ();} EXz5Rue LV
catch(Exception e){e.printStackTrace ();} tK&.0)*=
} )2X ng_,
X-di^%<
ZyqTtA!A
//读取保存的下载信息（文件指针位置） JL1%XQ i
private void read_nPos() z"BV+
{ rVkoj;[
try{ |Iy55~hK`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OwGl&
int nCount = input.readInt(); t/cjz/]
nStartPos = new long[nCount]; 1r}fnT<
nEndPos = new long[nCount]; =+gp~RR,
for(int i=0;i<nStartPos.length;i++) NF=FbvNe
{ /p') u3
nStartPos = input.readLong(); @]f"X>
nEndPos = input.readLong(); . FT*K[+ih
} n<:/ X tE
input.close(); #)%N+Odnr
} zOq~?>Ms6
catch(IOException e){e.printStackTrace ();} )@Yp;=l
catch(Exception e){e.printStackTrace ();} f}bUuQrH-!
} ]>@; 2%YvY
l;>#O
V"VWHAu*.w
private void processErrorCode(int nErrorCode) 3OHP-oa.
{ 9frx60
System.err.println("Error Code : " + nErrorCode); r @~T}<I
} -"5x? \.{m
o}5:vi]
Yfy6o6*:
//停止文件下载 8xmw-s)
public void siteStop() #&">x7?5
{ $P]%Px!x
bStop = true; HSx~Fs^J
for(int i=0;i<nStartPos.length;i++) c1/Gyq
fileSplitterFetch.splitterStop(); Sm#;fx+
vII&v+C
U-TwrX
} H<`[,t
} *Rshzv[
//负责部分文件的抓取 *MkhRLw\,
**FileSplitterFetch.java 6__@?XzJ
*/ L}AR{
package NetFox; q9qmz[
<C6/R]x#
lg;Y}?P
import java.io.*; `<t{NJ&f
import java.net.*; 'O`jV0aa'
;:*o P(9k
{549&]/o
public class FileSplitterFetch extends Thread { "}K/ b
BmrP]3W?
}Iub{30mp
String sURL; //File URL 5S7`gN.
long nStartPos; //File Snippet Start Position 17{]QuqNF
long nEndPos; //File Snippet End Position ^g[\.Q
int nThreadID; //Thread's ID nx=#QLi
boolean bDownOver = false; //Downing is over "<6pp4*I
boolean bStop = false; //Stop identical [RD ^@~x
FileAccessI fileAccessI = null; //File Access interface !gy'_Y
Hi|2z5=V
<Xy8}Z`s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oAWk<B(@
{ QAi(uL5
this.sURL = sURL; Yx&cnDx
this.nStartPos = nStart; J+\F)k>r
this.nEndPos = nEnd; ,@='.Qs4g
nThreadID = id; ao{>.b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P; }Z 3!
} B\|>i~u(
v}zo vEi
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public void run() zx-+u7qKH
{ :G^`LyOM
while(nStartPos < nEndPos && !bStop) ENC_#-1x
{ =(v!pEF
F.A<e #e?
^&&dO*0{
try{ g) v"nNS
URL url = new URL(sURL); n{BC m %
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ejo4mQ]a
httpConnection.setRequestProperty("User-Agent","NetFox"); j)-D.bY0
String sProperty = "bytes="+nStartPos+"-"; ZX-9BJ`Q
httpConnection.setRequestProperty("RANGE",sProperty); jT::o
Utility.log(sProperty); JIb<>X,
Pms3X
xOT'4v&.
InputStream input = httpConnection.getInputStream(); xxkP4,(p
//logResponseHead(httpConnection); 9,`mH0jP
,zXL8T
#EHBS~^
byte[] b = new byte[1024]; qoZ*sV
int nRead; 6j"(/X|Ex5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +8^9:w0}
{ [=U7V;5($
nStartPos += fileAccessI.write(b,0,nRead); 20?i4h_
//if(nThreadID == 1) =_":Z!_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V2VsJ
} h!K B%4V
IJ4"X#Q/
%-A8`lf<
Utility.log("Thread " + nThreadID + " is over!"); 2)j\Lg_M
bDownOver = true; b V9Z[[\
//nPos = fileAccessI.write (b,0,nRead); Ysr{1!K
} ys#M* {?
catch(Exception e){e.printStackTrace ();} eaX`S.!jR
} ePs<jrB<
} <;=Y4$y[
J+IW
tMAa$XrZj
//打印回应的头信息 /kw4":{]
public void logResponseHead(HttpURLConnection con) >t D-kzN
{ ik$wS#1+L
for(int i=1;;i++) J~_p2TZJ\3
{ 2M&4]d
String header=con.getHeaderFieldKey(i); i[\[xfk
if(header!=null) >^-[Mpa(*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,xTbt4J
Utility.log(header+" : "+con.getHeaderField(header)); k2t?e:)3zr
else w:Lu
break; _23sIUN c3
} ;*Rajq
} NWAF4i&$
Xx'>5d>
y5Pw*?kn
public void splitterStop() gE ,j\M*
{ WN?T*bz2
bStop = true; fwq|8^S@
} ^mJvB[ u|
e< CPaun
"^XN"SUw
} Q}=RG//0*
3Aj_,&X.@(
c%Gz{':+
/* zr[~wM
**FileAccess.java 19N:9;Ixz
*//文件访问(定位，写) Bw_Ih|y,w
package NetFox; &)X<yd0
import java.io.*; <rC#1wR4
KPR{5
3?O|X+$p
public class FileAccessI implements Serializable{ @wFm])}0
Cfi2N V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z9'0&G L
RandomAccessFile oSavedFile; 9~; Ju^b
long nPos; xlwsZm{V
'I<j`)4`d
L3GJq{t
public FileAccessI() throws IOException 'D/AL\1{p(
{ +.N;h-'
this("",0); bv+e'$U3
} * QR7t:([
Hug{9Hr3.
7S1!|*/ I
public FileAccessI(String sName,long nPos) throws IOException Dw#&x/G
{ e{}o:r
oSavedFile = new RandomAccessFile(sName,"rw"); 8 6+>|
this.nPos = nPos; DA wzXsx
oSavedFile.seek(nPos); (mD]}{>
} SW; bE
]rNfr-
+[qkG. O
public synchronized int write(byte[] b,int nStart,int nLen) L_.}z)S[\
{ u!-eP7;7
int n = -1; 0*AlLwO
try{ <+b:
oSavedFile.write(b,nStart,nLen); +>3c+h,%.
n = nLen; rx;U/)~#<
} W" !amMQ
catch(IOException e) 62_$O"
{ i4pJIb
e.printStackTrace (); 0K2[E^.WN
} :RQ[(zD]
# R&[+1=9j
sy`s$Ed!
return n; 6wd]X-G++
} &7W6IM
g.]'0)DMW
i\Vpp8<B
} dJ!o/y6
</=PN1=A
e||_j
/* vjb?N
**SiteInfoBean.java l xfdJNb
*/ LC7LO
package NetFox; d0=nAZZ
^pjez+
y|dXxd9
public class SiteInfoBean { z3C^L
:=Q|gRTL*
>gZz`CH
private String sSiteURL; //Site's URL +B m+Pj>
private String sFilePath; //Saved File's Path yq}{6IyZ^
private String sFileName; //Saved File's Name k:TfE6JZ
private int nSplitter; //Count of Splited Downloading File w!}1oy
9CNHjs+-}s
.+Ej%|l%
public SiteInfoBean() Tpukz_F
{//nSplitter的缺省值为5 8joQPHkI\
//default value of nSplitter is 5 ^ ?=K)
this("","","",5); ptR
} 752wK|o0|;
h9I)<_}R
C6VoOT)\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \uk#pL
{ FZ9<Q
sSiteURL= sURL; %wf|nnieZ
sFilePath = sPath; #CPPdU$
sFileName = sName; `X='g96C1
this.nSplitter = nSpiltter; {h"\JI!
YBD{l
`I8^QcP
} .A\\v6@
o"FiM5L^.
mr!I}I7x&x
public String getSSiteURL() sAoM=n}!
{ mM}Ukmy
return sSiteURL; n@;x!c< +
} FIjET1{
rcZ SC3
2?T:RB}
public void setSSiteURL(String value) XKX,7
{ Pm^N0L9?q
sSiteURL = value; tb0E?&M
} DOVX$N$3
F2$bUY
r^t{Ii~
public String getSFilePath() CS\tCw\Y
{ kI3zYD^:
return sFilePath; B)]{]z0+`
} DBBBpb~~
Mlw9#H6
\Byk`} 9
public void setSFilePath(String value) 7f%Qc %B
{ 0l:pWc
sFilePath = value; Ue#yDTjc
} uq4sbkP
2A}uqaF
bH/pa#G(
public String getSFileName() 2 dD<]
{ loUwRz
return sFileName; _S2^;n?
} (kQ.tsl
OawrS{
BZ+ mO
public void setSFileName(String value) yVI;s|jG
{ cNo4UZvr
sFileName = value; 2c~?UK[1
} z|]oM#Gt
S"^KJUUc
//M4Sq(
public int getNSplitter() %HF$
{ '?G[T28
return nSplitter; ^wF@6e7/&
} Z!-<rajl
bEQtVe@`
to!W={S<ol
public void setNSplitter(int nCount) q9brpbg_
{ dA)4(0o8fD
nSplitter = nCount; <`xRqe:&9
} ]X: rby$
} @yn^6cE
{?f^
JXY!c\,
/* *[xNp[4EU
**Utility.java (Cl`+ V
*/ Iq0 #A5U%
package NetFox; L.0} UXd
r$r&4dY
L_gsG|xX
public class Utility { Kcw1uLb
2rj/wakd
n$jf($*
public Utility() jAOD&@z1
{ 5h>t4 [~
l(?Yx
* TR~>|
} 6WEu(}=
1a;&&!X
//线程睡眠 BXX1G
public static void sleep(int nSecond) 9p9-tJfH.
{ R,ddH[3
try{ }$1Aw%p^
Thread.sleep(nSecond); Gq^#.o]
} {y7,n
catch(Exception e) ii]'XBSVd
{ fSzX /r
e.printStackTrace (); 21G:!t4/?n
} C6wlRvWn
} n`g:dz
RYKV?f#[H
//日志 +hd1|qa4
public static void log(String sMsg) 2`w\<h
{ s`"ALn8m
System.err.println(sMsg); .X(ocs$}
} G/C5o=cY
0!,)7
N0G-/
public static void log(int sMsg) z/t:gc.
{ \l8$1p
System.err.println(sMsg); d<l-Ldle
} {cBLm/C
} G.c@4Wz+
?4}EhXR(
_G5MQ%z
/* yy-\$<j
**TestMethod.java +qEvz<kch
*/ !T3Esv
package NetFox; Ig6>+Mw
mLn =SU{#
rKys:is
public class TestMethod { :cK;|{f
R0*+GIRA(
a4M`Bk;mb
public TestMethod() R!.HS0i.
{ ///xx/weblogic60b2_win.exe c~UYs\
try{ ^6 sT$set
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |_;Vb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D;Jb'Be
SiteFileFetch fileFetch = new SiteFileFetch(bean); v`$9;9
fileFetch.start(); #Rdq^TGMi;
} nNff~u)I
catch(Exception e){e.printStackTrace ();} K*Tvo`
GcPhT
md/Z[du:'
} k&P_ c
GX lFS#`
'yM)>]u"
public static void main(String[] args) $zBG19 [%
{ \HOOWaapN
new TestMethod(); Lay+)S.ta[
} B1A5b=6G<
} HSOdqjR*
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