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)); dUgrKDNyA
} Uq_j\A;c
for(int i=0;i<nEndPos.length-1;i++) '/Bidb?
{ Ogt]_
nEndPos = nStartPos[i+1]; !{n<K:x1
} 6J~12TU,
nEndPos[nEndPos.length-1] = nFileLength; X1[CX&Am
} j#~Jxv%n
} gw`B"c|
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^[Ua46/"m
//启动子线程 )yY6rI;:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b5IA"w
for(int i=0;i<nStartPos.length;i++) 9%ii '{
{ FEPXuCb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Glq85S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]nQt>R p_
nStartPos,nEndPos,i); r!P}u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2>-S-;i
fileSplitterFetch.start(); o47r<>t
} RO0>I8c1c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Y)PU=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S0g'r !;6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @ DZD
nEndPos = " + nFileLength); O9'x-A%
// fileSplitterFetch[nPos.length-1].start(); ; UiwH
MRr</o
\ 6EKgC1
//等待子线程结束 LAx4Xp/
//int count = 0; 1iL'V-y
//是否结束while循环 0w'j+
boolean breakWhile = false; Et"?8\"n7
B .TB\j
FVv8--
while(!bStop) 4$/i%B#ad
{ .t&R>9cZ^
write_nPos(); Mfk2mIy
Utility.sleep(500); (3[z%@I
breakWhile = true; 7@.cOB`y@3
1[*UYcD
<]C$xp<2
for(int i=0;i<nStartPos.length;i++) Nf3.\eR
{ Bb&^{7
if(!fileSplitterFetch.bDownOver) G>YAJo
{ (vR 9H(#
breakWhile = false; <?D[9Mk$
break; IfO;S*Qt
} *F>v]8
} !@u>A_
if(breakWhile) 30PZ{c&Rll
break; e&ANp0|W
RUCPV[{b
#B'aU#$u
//count++; + SZYg[
//if(count>4) 'B83m#HR#
// siteStop(); VHOfaCE
} xRuFuf8
C ]Si|D
6m.k;'
System.err.println("文件下载结束！"); ES<1tG
} GN#<yv$av
catch(Exception e){e.printStackTrace ();} in<Rq"L
} "+KJop
gu)=wu0
}],Z;:
//获得文件长度 ` b !5^W
public long getFileSize() O2{)WWOT
{ lcON+j
int nFileLength = -1; h@7FY
try{ ?^' 7+8C*J
URL url = new URL(siteInfoBean.getSSiteURL()); UE _fpq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _u"nvgVz9
httpConnection.setRequestProperty("User-Agent","NetFox"); zeP}tzQO
9[v1h,L
)f+U~4G&
int responseCode=httpConnection.getResponseCode(); _a_xzv'
if(responseCode>=400) 2c<&eX8"
{ :J}t&t
processErrorCode(responseCode); M-NV_W&M
return -2; //-2 represent access is error 0U66y6
} )PkNWj6%y
-B#yy]8
g]*
String sHeader; eRbGZYrJ
^n#1<K[E
|eoid?=
for(int i=1;;i++) qo+N,x9o
{ &m3.h!dq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;TQf5|R\K
//Utility.log(in.readLine()); qZ@0]"h
sHeader=httpConnection.getHeaderFieldKey(i); zWw2V}U!
if(sHeader!=null) BhpOXqg
{ A6<C-1 N}j
if(sHeader.equals("Content-Length")) 8pM>Co!
{ L+B?~_*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OYM@szM
break; pDPxl?S
} d lH$yub
} nM=e]qH
else Y**|N8e
break; QH4wUU3X
} a\kb^D=T
} w&Dv8Wv+Oq
catch(IOException e){e.printStackTrace ();} ?&WYjTU]H
catch(Exception e){e.printStackTrace ();} `T/~.`R
LW#M@
t{!
Utility.log(nFileLength); T1B|w"In
g1(Xg.
]!1OH |Ad
return nFileLength; +ww^ev%
} K*K1(_x=
5_K5?N
Xog/O i
//保存下载信息（文件指针位置） Jsg I'
private void write_nPos() 8B!aO/Km
{ h*0S$p<[1
try{ {s,+^7
output = new DataOutputStream(new FileOutputStream(tmpFile)); <j}lp-
output.writeInt(nStartPos.length); I9$c F)zk
for(int i=0;i<nStartPos.length;i++) XXmE+aI
{ $ E1Tb{'
// output.writeLong(nPos); )j6eE+gF
output.writeLong(fileSplitterFetch.nStartPos); Q^}%c U0
output.writeLong(fileSplitterFetch.nEndPos); L^kp8o^$
} +5<k-0v
output.close(); Kj=gm .
} WV;=@v
catch(IOException e){e.printStackTrace ();} fbrp#G71y
catch(Exception e){e.printStackTrace ();} 1Wg-x0R
} ,zcQS-e2
[}nK"4T"Ri
m:tiY [c>W
//读取保存的下载信息（文件指针位置） %/"Oxi^G
private void read_nPos() Gtv,Izt
{ qOCJTOg7
try{ Q>}2cDl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )G^TW'9
int nCount = input.readInt(); 1F[L"W;r
nStartPos = new long[nCount]; |wxGpBau
nEndPos = new long[nCount]; ~KjJ\b)R
for(int i=0;i<nStartPos.length;i++) ofc.zwH
{ a<XCNTaVT
nStartPos = input.readLong(); =<f-ob8,
nEndPos = input.readLong(); jdut4 nFc
} $X`y%*<<v
input.close(); CF y}r(q
} $KV&\Q3\0
catch(IOException e){e.printStackTrace ();} KcGsMPJ
catch(Exception e){e.printStackTrace ();} xtV[p4U
} +%J\y^09kr
"yb WDWu
z,;;=V6j
private void processErrorCode(int nErrorCode) *a}(6Cx
{ =Je>`{J
System.err.println("Error Code : " + nErrorCode); `T*U]/zQ
} hi{%pi&!T
V+MK'<#B
D _X8-
//停止文件下载 &!.HuRiuC
public void siteStop() iMP
{ 0V,Nv9!S
bStop = true; )yee2(S
for(int i=0;i<nStartPos.length;i++) MKGS`X]<J
fileSplitterFetch.splitterStop(); 4k}e28
-Q e~)7
@B1{r|-<^
} jjOgG-Q
} s}x>J8hK
//负责部分文件的抓取 IxSV?k
**FileSplitterFetch.java >X}{BDMb.
*/ V%L/8Q~
package NetFox; g1m-+a
GrEs1M1]*
sPYX~G&T
import java.io.*; `{<frB@
import java.net.*; pck>;V
o.:p_(|hI
~GB=Nz
public class FileSplitterFetch extends Thread { 85U.wpG
_"f :`
'E]A.3-Mt
String sURL; //File URL Ng<1Sd|MV
long nStartPos; //File Snippet Start Position :{g7lTM
long nEndPos; //File Snippet End Position g#^|oYuH6
int nThreadID; //Thread's ID /F[+13C
boolean bDownOver = false; //Downing is over `_AM` >_
boolean bStop = false; //Stop identical 0LVE@qEL
FileAccessI fileAccessI = null; //File Access interface 0A$SYF$O+[
oN2=DYC41
,\ldz(D?+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CDg AGy
{ 60B-ay0e$b
this.sURL = sURL; rnhFqNT:
this.nStartPos = nStart; Bt~s*{3$8
this.nEndPos = nEnd; E{^^^"z P
nThreadID = id; :xeLt;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IhonnLLW
} L ^Y3=1#"g
Z[#IfbYt
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public void run() n[k1np$7?6
{ T-L5zu
while(nStartPos < nEndPos && !bStop) d+2daKi
{ m@qqVRn#)
\P?ToTTV
L/r{xS
try{ R9dP,<2
URL url = new URL(sURL); ym%slg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Df=q-iq<{/
httpConnection.setRequestProperty("User-Agent","NetFox"); TQ9'76INb
String sProperty = "bytes="+nStartPos+"-"; 1p\Ak
httpConnection.setRequestProperty("RANGE",sProperty); qc8Ta"
Utility.log(sProperty); )s")y
&sOM>^SAD
av'*u
InputStream input = httpConnection.getInputStream(); Wc'Ehyi;
//logResponseHead(httpConnection); vZjZb(jlN
: }?{@#Z
#s"B-sWE
byte[] b = new byte[1024]; #}o<v|;
int nRead; 'Ji+c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i^|@"+
{ 4,}GyVJFb`
nStartPos += fileAccessI.write(b,0,nRead); MV936
//if(nThreadID == 1) I-:`cON=G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D s-`
} y4F^|kS) [
,b'4CF
#ooc)),
Utility.log("Thread " + nThreadID + " is over!"); f'{>AKi=C
bDownOver = true; <MZi<Z`
//nPos = fileAccessI.write (b,0,nRead); 'U)8rR
} :m`/Q_y"
catch(Exception e){e.printStackTrace ();} %g^"]
} sbla`6Fb
} rihlae5Kz
tV`&-H
Pz473d
//打印回应的头信息 {'~sS
public void logResponseHead(HttpURLConnection con) 'j79GC0
{ %W;u}`
for(int i=1;;i++) c^S&F9/U*
{ Es;;t83p
String header=con.getHeaderFieldKey(i); \3^Pjx
if(header!=null) 7%CIt?Z%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9~Xg#{
Utility.log(header+" : "+con.getHeaderField(header)); Fk$@Yy+}e
else Y><(?
break; D@hmO]5c
} (!n-Age
} )BLmoJOf
U42\.V0
5Rs?CVVb
public void splitterStop() r<(kLpOH%
{ E^syrEz
bStop = true; /=M.-MU2
} v MWC(m
"k>bUe|RG
~&~C#yjg1
} Y'_ D<Mp
g{a d0.y,
hEcYpng~
/* )6G+tU'
**FileAccess.java |Ow$n
*//文件访问(定位，写) Oxn'bh6R0
package NetFox; 4TJ!jDkox
import java.io.*; r,nn~
tJ>d4A;8x
<4NQL*|>
public class FileAccessI implements Serializable{ R6Pz#`n
bX{PSjD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g =\13#F
RandomAccessFile oSavedFile; SRk7gfP*q
long nPos; r %xB8e9
j?J=w=.Nx
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public FileAccessI() throws IOException Na;t#,
{ w{ m#Yt
this("",0); 4H9xO[iM
} Kz^hQd
:wCC^Y]
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public FileAccessI(String sName,long nPos) throws IOException SD I,M
{ Bcm=G""
oSavedFile = new RandomAccessFile(sName,"rw"); %#Q #N,fw
this.nPos = nPos; 7eH@n<]Y2
oSavedFile.seek(nPos); /2'c>
} qid1b b
A'v[SUW'm
_Fvsi3d/
public synchronized int write(byte[] b,int nStart,int nLen) Px#4pmz
{ Sh47c4{
int n = -1; m[#%/
try{ =z%s8D2
oSavedFile.write(b,nStart,nLen); m-#d8sD2C
n = nLen; ]=pWZ~A
} 3DHvaq q7
catch(IOException e) {8i}Ow
{ ~pwY6Q
e.printStackTrace (); ~l4Q~'
} Cj=J;^vf
b6$4Ul-.
,dq`EsHg`M
return n; {&b-}f"m
} ^)'||Ly
,DQ >&_DK
],#ZPUn
} m&{rBz0
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^:$j:w?j
/* 5[hlg(eb
**SiteInfoBean.java )S"o{N3B
*/ dR?5$V(
package NetFox; s={X-H< 2
kfIbgya
&A#90xzF
public class SiteInfoBean { D`5: JR-{
5vl2yN
EID(M.G
private String sSiteURL; //Site's URL Kjvs@~6t
private String sFilePath; //Saved File's Path ob)D{4B'
private String sFileName; //Saved File's Name 7{8)ykBU^
private int nSplitter; //Count of Splited Downloading File 13]y)(
34^Q5B~^J
SwQOFE/Dv~
public SiteInfoBean() @V*au:
{//nSplitter的缺省值为5 U@MOvW)
//default value of nSplitter is 5 $Jt8d|UP
this("","","",5); cbY3mSfn*
} &s_}u%iC
F\l!A'Q+t
ROcY'-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VdYOm
{ :K5V/-[|V1
sSiteURL= sURL; f2 VpeJ<p
sFilePath = sPath; FxMMxY,*%
sFileName = sName; S:DcfR=a
this.nSplitter = nSpiltter; + 4++Z
d u_O}x
vHoT@E#}'
} !k ;[^>
',<{X(#(
P[r}(@0rJ
public String getSSiteURL() A89Y;_4y
{ 4{uJ||!
return sSiteURL; vjY);aQ
} R#rh
\Gv-sA
s"gKonwI2
public void setSSiteURL(String value) 15RI(BN
{ Hd96[Uo
sSiteURL = value; B/[hi%~
} ^!XU+e+:0
HE4`9$kVLr
qLU15cOM
public String getSFilePath() Ul7,k\q@
{ ||bA
return sFilePath; 3ytx"=B%
} 5QCw5N
F^J&g%ql
0fEZD$
public void setSFilePath(String value) xow6@M,
{ dpl"}+
sFilePath = value; Vu^Q4Z
} 2*b#+b
!^rITiy
gt(X!iN]
public String getSFileName() Ss*LgK_
{ R A-^!4tX
return sFileName; ~M|NzK_9
} $L $j KNwf
<[*h_gE5
;5zjd,
public void setSFileName(String value) pO@k@JZ
{ +^o3}`
sFileName = value; 0$Qn#K
} xV }:M
Wl@0TUK
S S7D1
public int getNSplitter() x|P<F2L
{ |sDG>Zq?
return nSplitter; T=iZ9w
} 7l4InR]
@Wlwt+;fT
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public void setNSplitter(int nCount) 1`7]C+Pv
{ +"*l2E]5
nSplitter = nCount; IDL^0:eg<.
} y'i:%n}I
} bF8xQ<i~Y
t(LlWd
6=aBD_2@
/* mUe@Dud
**Utility.java o%9Ua9|RR
*/ k1@ A'n
package NetFox; wjw<@A9
l=<F1Lz
R oF
public class Utility { v{\n^|=])
Es ZnGuY
iLI.e rm
public Utility() 1GyAQHx,
{ K%.YNVHHC
xOX*=Wv
(PE8H~d
} d[qEP6B
%s&E-*X
//线程睡眠 &,6y(-
public static void sleep(int nSecond) hc31+TL
{ P*nT\B
try{ @pEO@bbg>
Thread.sleep(nSecond); EzeDShN=J
} 9cx!N,R t
catch(Exception e) GwU>o:g"
{ vb80J<4
e.printStackTrace (); b*F :l#
} AU${0#WV_
} /oixtO)
C$Hl`>?$
//日志 $=S'#^Z
public static void log(String sMsg) /^es0$Co.
{ ,EGD8$RA]
System.err.println(sMsg); d >wmg*J
} xSMp[j
SBYMDKZ
8=zM~v)
public static void log(int sMsg) p.W*j^';Q
{ ^7^bA
System.err.println(sMsg); 9^[5!SMzCj
} 0;m$a=
} y9l.i@-
h(N9RJ}
J=Y( *D7Q
/* [?K\%]
**TestMethod.java zi DlJ3]^
*/ {"@b`
package NetFox; 7! A%6
V?L$ys
b&V]|Z(
public class TestMethod { &j~|3
.]sIoB-54
\i;~~;D
public TestMethod() 1\.zOq#
{ ///xx/weblogic60b2_win.exe IP4b[|ef
try{ H2pXJ/XF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ba)YbP[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ns(L1'9=
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vlxb<$5Nh
fileFetch.start(); yPxG`w'
} XCi]()TZ_
catch(Exception e){e.printStackTrace ();} j*Wh;I+h
'2qxcco
-aeo7C
} l1|,Lr
Gk]qE]hi
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public static void main(String[] args) ^*UfCoj9Z
{ W$VCST
new TestMethod(); GO GXM4I
} G]NtX4'4
} >7Sl( UY-
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