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)); y6Ez.$M
} lMcO2006L
for(int i=0;i<nEndPos.length-1;i++) @bChJl4
{ v+o6ZNX
nEndPos = nStartPos[i+1]; '}:(y$9.`
} ].sD#~L_
nEndPos[nEndPos.length-1] = nFileLength; C-g,uARX(r
} Z<QNzJ D
} pH(X;OC9S
sp+'c;a
,3!TyQ\m'
//启动子线程 3!%-O:!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E)wf'x
for(int i=0;i<nStartPos.length;i++) PXML1.r$Q
{ e,d}4 jy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @|s$:;(=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HU$]o N
nStartPos,nEndPos,i); F'CJN$6Mw/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uG/'9C6Z
fileSplitterFetch.start(); &[SFl{fx>-
} brG!TJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KT+{-"4-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0/1=2E^,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %gj7KF
nEndPos = " + nFileLength); [WV&Y,E
// fileSplitterFetch[nPos.length-1].start(); f>e0l'\
hQ@#h`lS
{&L^|X
//等待子线程结束 Fnay{F8z
//int count = 0; )l/ .<`|
//是否结束while循环 5>UQ3hWo
boolean breakWhile = false; ia-ht>F*;
k~I]Y,
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while(!bStop) %dzO*/8cWo
{ ]{|lGtK %
write_nPos(); Q [C26U
Utility.sleep(500); #,97 ]
breakWhile = true; |'I>Ojm
KW3<5+w]c
<L<^uFB
for(int i=0;i<nStartPos.length;i++) u /DE
{ q*tGlM@R?
if(!fileSplitterFetch.bDownOver) bZ:xH48MY
{ F1BXu@~e(
breakWhile = false; Ni|MTE]~
break; !%$,S=_F
} Xfbr;Jt"<
} B/o8r4[80
if(breakWhile) C+"c^9[
break; HF"TS*
IP@3R(DS%
U$3DIJVI
//count++; 8@LUL)"
//if(count>4) 8nL9#b
// siteStop(); SlHDBr!.z
} t0r0{:
+@yU `
oI'& &Bt
System.err.println("文件下载结束！"); Ab>Kfr#
} ]mz'(t
catch(Exception e){e.printStackTrace ();} (h@!_qi9:
} /y|ZAN
7U?#Xi5
*j,bI Y&se
//获得文件长度 :U=3*f.{
public long getFileSize() )WW*X6[k
{ R eb.x_
int nFileLength = -1; Q1ayd$W@<
try{ <mj/P|P@
URL url = new URL(siteInfoBean.getSSiteURL()); l9OpaOVfJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dsn=fht
httpConnection.setRequestProperty("User-Agent","NetFox"); m*CW3y{n)
^fH)E"qq5
/8nUecr
int responseCode=httpConnection.getResponseCode(); z>iXNwz"?
if(responseCode>=400) 1P'A*`!K
{ 'Bxj(LaV-
processErrorCode(responseCode); 0 f$96sl
return -2; //-2 represent access is error G 9(*F
} JtsXMZz
R4P&r=?
>)G[ww[
String sHeader; YllZ5<}
MkjB4:"
"'@D\e}
for(int i=1;;i++) 7Z~JuTIZ
{ *9xxX,QT8Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RgJbM\`}?
//Utility.log(in.readLine()); q5JQx**g
sHeader=httpConnection.getHeaderFieldKey(i); fA]sPh4Uag
if(sHeader!=null) 023uAaI^3r
{ ~d1=_p:~T
if(sHeader.equals("Content-Length")) x X[WX#'f
{ XjP&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /#SfgcDt
break; 9_F&G('V{a
} ]7>#YKH.
} l6 }+,v@#
else f~PS'I_r
break; 7R m\#
} NZ&ZK@h}.
} UKV<Ye|
catch(IOException e){e.printStackTrace ();} x?lRObHK
catch(Exception e){e.printStackTrace ();} `LLmdm 6i
/5z,G r
" DLIx}
Utility.log(nFileLength); 5c(g7N
"C&>$h_%
54JZOtC3~
return nFileLength; F?"Gln~;
} n4M Xa()P1
_9H]:]1QH
d>W#c8X>
//保存下载信息（文件指针位置） {.p;V
private void write_nPos() ?U[6X|1
{ i2rSP$j
try{ (n~fe-?}8
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y\WVkd(+G
output.writeInt(nStartPos.length); lY(_e#
for(int i=0;i<nStartPos.length;i++) >ov#\
{ R@s|bs?
// output.writeLong(nPos); i+in?!@G:
output.writeLong(fileSplitterFetch.nStartPos); !Q_Wbu\U
output.writeLong(fileSplitterFetch.nEndPos); G`jvy@
} b_6cK#
output.close(); K]Vp! G
} )=X g
catch(IOException e){e.printStackTrace ();} MffCk!]
catch(Exception e){e.printStackTrace ();} QV HI}3~
} ='w 2"4
2Xk;]-T!
r|*_KQq
//读取保存的下载信息（文件指针位置） B(vCi^
private void read_nPos() Z<^EZX3N
{ [7~AWZU3
try{ J$5G8<d>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?Js4\X!uJ
int nCount = input.readInt(); gq 3|vzNZ
nStartPos = new long[nCount]; B8"c+<b
nEndPos = new long[nCount]; @#hvQ6u
for(int i=0;i<nStartPos.length;i++) =M4:nt
{ iR./9}Ze
nStartPos = input.readLong(); =T6 ~89
nEndPos = input.readLong(); ^b`-zFL7
} O9_1a=M
input.close(); 8@(?E[&O>
} @_$$'XA7
catch(IOException e){e.printStackTrace ();} IHi[3xf<
catch(Exception e){e.printStackTrace ();} @Lf&[_
} >`a^E1)
Vp~ cN
6| o S 5
private void processErrorCode(int nErrorCode) v<g~EjzCf
{ p=A,yGDV
System.err.println("Error Code : " + nErrorCode); w xte
} Ab/JCZNn
D}X6I#U'/
wd<{%qK`{
//停止文件下载 g[t paQ
public void siteStop() R) dP=W*
{ r)Lm| S
bStop = true; &fWC-|
for(int i=0;i<nStartPos.length;i++) i^iu#WC
fileSplitterFetch.splitterStop(); 4k3pm&
$oM>?h_=
1L'Q;?&2H,
} 3RGmmX"?G
} `{h)-Y``
//负责部分文件的抓取 dR< d7
**FileSplitterFetch.java ",vK~m2W_
*/ EK[J!~
package NetFox; `[#id@Z1
]1>R8
TIl 'Z7
import java.io.*; 4@Db $PHs
import java.net.*; U*\K<fw
l4r>#n\yj
];6955I!
public class FileSplitterFetch extends Thread { 0asP,)i
{D..(f1*u
3(t,x
String sURL; //File URL z#PaQp5F
long nStartPos; //File Snippet Start Position ru9@|FgAE
long nEndPos; //File Snippet End Position (>ze{T|
int nThreadID; //Thread's ID F<6(Hw#>
boolean bDownOver = false; //Downing is over }v|_]
boolean bStop = false; //Stop identical F:P2:s<d-
FileAccessI fileAccessI = null; //File Access interface rb4;@&
`o }+2Cb
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oOvQAW8`
{ un~`|
this.sURL = sURL; l5VRdZ4Uf
this.nStartPos = nStart; & C)1(
this.nEndPos = nEnd; ,lvG5B\0
nThreadID = id; :2==7u7v?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^t7u4w!
} ]>Z9K@
||wi4TP
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public void run() DW9MX`!Xc
{ o_mjI:
while(nStartPos < nEndPos && !bStop) <dD!_S6@,
{ ~@l4T_,k
bfoTGi
uHZ4 @w:
try{ 6.KEe^[-
URL url = new URL(sURL); ] L#c <0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j[A(@w"
httpConnection.setRequestProperty("User-Agent","NetFox"); 'SlZ-SdR
String sProperty = "bytes="+nStartPos+"-"; =<Sn&uL
httpConnection.setRequestProperty("RANGE",sProperty); 3~3tjhw;]9
Utility.log(sProperty); NNqvjM-
k,=<G,
]N'%l]_$
InputStream input = httpConnection.getInputStream(); m3pDFI
//logResponseHead(httpConnection); W3>9GY90R
V-go?b`
F09%f"9
byte[] b = new byte[1024]; "h[)5V{
int nRead; 1`L.$T,1!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $"|r7n5[
{ 5m0lk|`
nStartPos += fileAccessI.write(b,0,nRead); 1~~GF_l?
//if(nThreadID == 1) a$Ud"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?K:\WW
} 0ElEaH1z
-`\^_nVC
{'M/wT)FeC
Utility.log("Thread " + nThreadID + " is over!"); #'>)?]tn
bDownOver = true; Bx5xtJ|!
//nPos = fileAccessI.write (b,0,nRead); |J:r]);@K
} #CI0G
catch(Exception e){e.printStackTrace ();} \rxjvV4fcZ
} z{w %pUn}
} G]k[A=dg
LkzA_|8:D
e>e${\=,
//打印回应的头信息 Bi \fB-|
public void logResponseHead(HttpURLConnection con) v.C
{ "PRHQW
for(int i=1;;i++) 8M,o)oH
{ =Jw*T[E
String header=con.getHeaderFieldKey(i); A~nqSe
if(header!=null) M_%KhK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hLZfArq}
Utility.log(header+" : "+con.getHeaderField(header)); A_U=`M=-
else XtZd% #2},
break; ibQ xL3
} j[dZ*Jr_
} zo"L9&Hzo
gvWgw7z
/LWk>[Z;
public void splitterStop() ;-py h(
{ hO.b?>3NL
bStop = true; Fy E#@ R
} xsRkO9x
`!I/6d?A
)=K8mt0qob
} YV|_y:-
A+dx7anUz
N.z2eo
/* l"dXL"h
**FileAccess.java c\rP -"C
*//文件访问(定位，写) }UGSE2^1
package NetFox; e4Ibj/
import java.io.*; OZf@cOTWK
T}Wbt=\M
u e
public class FileAccessI implements Serializable{ P#!gP3
NV/paoyx:*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 iOv>g-t:
RandomAccessFile oSavedFile; =e#h;x2
long nPos; n]4Elrxx
U.~G{H`G,u
s Y1@~v
public FileAccessI() throws IOException s=jH1^
{ ]C"?xy
this("",0); 9"S iHp\)
} e&i`/m5
%$o[,13=
J?Y,3cc.
public FileAccessI(String sName,long nPos) throws IOException /2=9i84
{ w<!,mL5 N
oSavedFile = new RandomAccessFile(sName,"rw"); 3p HI+a
this.nPos = nPos; q+8de_"]
oSavedFile.seek(nPos); c9jS !uDMK
} #0h}{y E
7n84`|=
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public synchronized int write(byte[] b,int nStart,int nLen) "eTALRL'o
{ (m!kg
int n = -1; ~V?z!3r-)
try{ a;; Es
oSavedFile.write(b,nStart,nLen); H6nH
n = nLen; Q -$) H;,
} D[]0/+,
catch(IOException e) Io IhQ
{ K>~YO~~
e.printStackTrace (); !+Y+P?
} K0vS
ZVdQ$
( 6zu*H)
return n; JBc*m
} B<.\^fuS
Zz:%KUl3
& uwOyb
} 5"b1: w@
c}S<<LR
}JQy&V%
/* {*8G<&
**SiteInfoBean.java {=d}04i)E"
*/ j$6Q]5KdoS
package NetFox; &CXk=Wj
hop| xtai;
Au)~"N~p?
public class SiteInfoBean { *6u2c%^
byt$Wqdl
LTA0WgzR)
private String sSiteURL; //Site's URL F}[!OYyg
private String sFilePath; //Saved File's Path .C+(E@eyA
private String sFileName; //Saved File's Name #Q=c.AL{
private int nSplitter; //Count of Splited Downloading File BaP'y8dVN
SQ+r'g
jvR(e"
public SiteInfoBean() 0cfGI%
{//nSplitter的缺省值为5 `?l /HUw
//default value of nSplitter is 5 rk;]7Wu
this("","","",5); T]/>c
} EAWBgOO8iC
yeIS}O
eAP 8!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qvWi;
{ e9Gu`$K
sSiteURL= sURL; ndN*X'
sFilePath = sPath; x2HISxg
sFileName = sName; %Q}(.h%M
this.nSplitter = nSpiltter; 2g_mQT
(5+g:mSfr
726UO#*
} R@Gll60
>PQ?|Uk
v}AjW%rB
public String getSSiteURL() '+iLW~
{ ]b1>bv%
return sSiteURL; 69:-c@L0
} !z2xm3s{]p
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j5/|1N
public void setSSiteURL(String value) {<}Hut:a
{ H4YA
sSiteURL = value; O<@L~S]
} GA[bo)"
Ijz*wq\s;
g6.I~oQj
public String getSFilePath() Z1$U[Tsd
{ 8D?$@!-
return sFilePath; ~FXq%-J
} 7\nXJ381
S&[9Vb
EASmB
public void setSFilePath(String value) ; 5[W*,7s
{ z`Nss o=
sFilePath = value; $txF|Fj]^A
} uz$p'Q
^k^?>h
~h=iZ/g_^_
public String getSFileName() %WmTG }L)
{ <*u^8lCA
return sFileName; @;hdZLG]`&
} `*kl>}$
AkO);4A;Jd
HKO]_; :(
public void setSFileName(String value) y | I9"R
{ X+,0;% p
sFileName = value; =_@) KWeX$
} ug;\`.nT^
){eQ.yW
jr#*;go
public int getNSplitter() E&@#*~
{ <_=O0 t|6
return nSplitter; c1y+kvv
} x7i<dg&
QSM3qke
R(P(G;#j
public void setNSplitter(int nCount) 0sme0"Sl
{ #QSSpsF@
nSplitter = nCount; Sx0{]1J
} @k'V`ZQF
} ^f"|<r
TVSCjI
Ux=B*m1@{
/* 0mmHN`<
**Utility.java gnxD'1_
*/ r[GH#vF;7
package NetFox; XsFzSm
WT1y7+_g(d
yxf#@Je"
public class Utility { $bZ-b1{c C
vo&h6'i>7
cg9}T[A
public Utility() z> DQ
{ iAXGf V
lHTr7uF(
oZl%0Uy?9I
} 15aPoxo>
7kT X
//线程睡眠 tuuwoiQ*`
public static void sleep(int nSecond) Gui[/iY,F
{ uf (_<~
try{ hJk:&!M=T
Thread.sleep(nSecond); %4YSuZg
} Vw`Q:qo0:b
catch(Exception e) Pv\8 \,B9
{ \l 8_aj
e.printStackTrace (); `Gl[e4U
} ?gvu E1
} E_Y!in 70
eU e, P
//日志 lq,]E/<&
public static void log(String sMsg) kDM?`(r
{ U&a(WQV9&
System.err.println(sMsg); 87!m l
} l7@cov
8]1,EE<
IJDbm}:/e
public static void log(int sMsg) +KNd%AJ
{ EdSUBoWF}
System.err.println(sMsg); zM<L_l&
} +qT+iHa|n
} 8$ #z>
m!P<# |V
@'?gan#(
/* a69e^;,>q
**TestMethod.java $MfRw
*/ ?<8c
package NetFox; \n^[!e"`
/<(-lbq,
KHJ wCv
public class TestMethod { C=cn.CX
]?oJxW.
[fo#){3K
public TestMethod() A^LS^!Jz
{ ///xx/weblogic60b2_win.exe 5IFzbL#q#f
try{ AP1ZIc6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z'}%Mkm`i}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }4h0{H
SiteFileFetch fileFetch = new SiteFileFetch(bean); :2C <;o
fileFetch.start(); >Q[ Z{
} +*Uv+oC|
catch(Exception e){e.printStackTrace ();} KU+\fwYpnk
7-~)/7L
~%f$}{
} k#8`996P
bw7gL\*
u7Ix7`V
public static void main(String[] args) LEOa=(mN\
{ )EKWsGNe/
new TestMethod(); .jtv Hr}U
} ]+B.=mO_
} &?Q^i">cZ
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