社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 10390阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* _Bp{~-fO  
**SiteFileFetch.java 6pHn%yE*  
*/ !\ckUMZ\  
package NetFox; `(rnD  
import java.io.*; vl{G;[6  
import java.net.*; AD ,  
cR0OJ'w  
e{"r3*  
public class SiteFileFetch extends Thread { ).BZPyV<  
<^APq8>  
X?'v FC  
SiteInfoBean siteInfoBean = null; //文件信息Bean X{j`H\'L  
long[] nStartPos; //开始位置 tTzPT<  
long[] nEndPos; //结束位置 {|;5P.,l  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 *}hx9:9\B  
long nFileLength; //文件长度 d0Jaa1b~O  
boolean bFirst = true; //是否第一次取文件 1+f>tv  
boolean bStop = false; //停止标志 gW[(gf.oo  
File tmpFile; //文件下载的临时信息 ;ORT#7CU  
DataOutputStream output; //输出到文件的输出流 [-*1M4D9  
BO3#*J5S\  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) e B$ S d  
public SiteFileFetch(SiteInfoBean bean) throws IOException Aw38T w  
{ Vl0 J!JK_  
siteInfoBean = bean; R*v~jR/   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); COF_a%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _Py/,Ks.q  
if(tmpFile.exists ()) '_n J DM  
{ ?-y!FD}m&  
bFirst = false; ? ^E B"{  
read_nPos(); Od?M4Ed(  
} QL<uQ`>(  
else kFJ sB,2-  
{ :2qUel\PEC  
nStartPos = new long[bean.getNSplitter()]; jP]I>Tq  
nEndPos = new long[bean.getNSplitter()]; B_^ ~5_0:  
} rM sd)  
]7*Z'E  
eC9nOwp]xH  
qM."W=XVN  
} M7\; Y  
DQ<{FN  
TTJFF\$?  
public void run() |\1!*Qp  
{ F|eKt/>e  
//获得文件长度 cWd\Ki  
//分割文件 MQ9Nn|4  
//实例FileSplitterFetch 5eZ8$-&([  
//启动FileSplitterFetch线程 -R~!N#y  
//等待子线程返回 HF3W,eaqK  
try{ K%XQdMv  
if(bFirst) ] Q 'Ed  
{ (-RZ|VdYg  
nFileLength = getFileSize(); 4oY<O  
if(nFileLength == -1) ^`W8>czi  
{ JAjXhk<=  
System.err.println("File Length is not known!"); +YL9gNN>P  
} {HJzhIgCf  
else if(nFileLength == -2) NA%(ZRSg(  
{ 'Xl_,; W]  
System.err.println("File is not access!"); i|z=q  
} Y7|R vLWoP  
else ST#OO!  
{ -P+@n)?T6  
for(int i=0;i<nStartPos.length;i++) BCw5.@HK*  
{ 6' 9ITA  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,qx;kJJ  
} sHk,#EsKH  
for(int i=0;i<nEndPos.length-1;i++) _K4Igq  
{ )FNvtLZ  
nEndPos = nStartPos[i+1]; 7O_@b$Q  
} _I("k:E7  
nEndPos[nEndPos.length-1] = nFileLength; h  0EpW5  
} #HMJBQ4v#  
} e|`QW|9 .  
QY]^^f  
U"1z"PcV  
//启动子线程 N36<EHq  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -Y*"!8  
for(int i=0;i<nStartPos.length;i++) mkA1Sh{hX>  
{ ])d_B\)Kck  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w]4=uL6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a(+.rf;  
nStartPos,nEndPos,i); TRQ@=.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &f}a`/{@  
fileSplitterFetch.start(); =%p%+F@RlW  
} a3&&7n  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]et4B+=i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <<43 'N+  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4LO U[D  
nEndPos = " + nFileLength); C%s+o0b  
// fileSplitterFetch[nPos.length-1].start(); -&PiD  
.'zXO  
o"O=Epg  
//等待子线程结束 8PWx>}XPt  
//int count = 0; K`=O!;  
//是否结束while循环 &WSxg&YG)\  
boolean breakWhile = false; f0uzoeL<%  
hJqLH ?Ri  
@a AR99M  
while(!bStop) `0l)\  
{ Dc,h( 2  
write_nPos(); ;Z\1PwT  
Utility.sleep(500); 1 11s%  
breakWhile = true; s "KPTV  
U@W3x@  
8 |>$M  
for(int i=0;i<nStartPos.length;i++) _j$"fg  
{ P\;L#2n  
if(!fileSplitterFetch.bDownOver) ^/|agQ7D2  
{ gy|L!_1Z8  
breakWhile = false; }T@^wY_Ow  
break; 1Sk=;Bic  
}  ~F?vf@k  
} "O{_LOJ  
if(breakWhile) _[zZm*  
break; =x9SvIm/tH  
dP>~ExYtm  
gyqM&5b  
//count++; VR86ok  
//if(count>4) 9FB[`}  
// siteStop(); ;x 9_  
} \8Mn[G9TL  
J~=bW\^I  
gbb2!q6p  
System.err.println("文件下载结束!"); BCDmce`=l  
} j]-0m4QF  
catch(Exception e){e.printStackTrace ();} v'R{lXE  
} _a;E>   
^*CvKCS  
3AKT>Wy =  
//获得文件长度 }6;K+INT  
public long getFileSize() v"nN[_T  
{ N?xZ]?T  
int nFileLength = -1; 6f"jl  
try{ HGuU6@~hu  
URL url = new URL(siteInfoBean.getSSiteURL()); 4o+SSS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _?j66-( Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); "I[a]T}/  
KpHt(>NR  
G.2\Sw  
int responseCode=httpConnection.getResponseCode(); rF9|xgFK  
if(responseCode>=400) `pMI @"m  
{ B3x4sK s  
processErrorCode(responseCode); gYeKeW3)  
return -2; //-2 represent access is error #@ClhpLD  
} ?]*WVjskE  
F52%og~N  
w}8 ,ICL  
String sHeader; icO$9c  
fQW1&lFT  
6Zr_W#SE  
for(int i=1;;i++) [HRry2#s  
{ 0ge"ISK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :;Lt~:0b~  
//Utility.log(in.readLine()); JD`IPQb~E  
sHeader=httpConnection.getHeaderFieldKey(i); xq6 eu 9   
if(sHeader!=null) 0bG[pp$[  
{ (p19"p  
if(sHeader.equals("Content-Length")) 6?;U[eV  
{ rJjNoY  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lN(|EI  
break; 1c5+X Cr  
} 2 m"2>gX  
} *5|;eN  
else 'E\/H17  
break; fL^$G;_?3  
} { l E\y9  
} L3/SIoqd  
catch(IOException e){e.printStackTrace ();} ]\ ~s83?X  
catch(Exception e){e.printStackTrace ();} 9"W3t]  
M]Kx g;  
~U;M1>  
Utility.log(nFileLength); f|v5i tO2  
T!f+H?6  
*VUD!`F  
return nFileLength; D(;jv="/  
} mNII-X G  
1Yk!R9.  
w@![rH6~F  
//保存下载信息(文件指针位置) >='y+ 68  
private void write_nPos() MyZ5~jnr\  
{ ;L*Ku'6Mt  
try{ `{oFdvL~)  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )%+7"7.  
output.writeInt(nStartPos.length); e,?qwZK:y  
for(int i=0;i<nStartPos.length;i++) +vr|J:  
{ +=Y[RCXT  
// output.writeLong(nPos); r!N> FE  
output.writeLong(fileSplitterFetch.nStartPos); "Wb>y*S   
output.writeLong(fileSplitterFetch.nEndPos); E%b*MU  
}  * Cj<Vy  
output.close(); Hhzi(<e^  
} ;hgRMkmz4<  
catch(IOException e){e.printStackTrace ();} ` t6|09e  
catch(Exception e){e.printStackTrace ();} I^GZ9@UE  
} @$7'{*  
_'mK=`>u  
oypF0?!m  
//读取保存的下载信息(文件指针位置) Z?f-_NHg  
private void read_nPos() V[;^{,;  
{ "$I8EW/1  
try{ )p`zN=t  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J1u&Ga  
int nCount = input.readInt(); Z#t}yC%^d  
nStartPos = new long[nCount]; yog(  
nEndPos = new long[nCount]; a7>^^?|  
for(int i=0;i<nStartPos.length;i++) PJ))p6 9  
{ Z]SUr`Z  
nStartPos = input.readLong(); X|'[\v2ld  
nEndPos = input.readLong(); wZg~k\_lF  
} ROr|n]aJj  
input.close(); X/f?=U  
} O~OM.:al&  
catch(IOException e){e.printStackTrace ();} S*NeS#!v  
catch(Exception e){e.printStackTrace ();} L2Fi/UWM  
} 4*&2D-8<K  
z7s}-w,  
r'<!wp@  
private void processErrorCode(int nErrorCode) 8dLK5"_3  
{ _Wtwh0[r*  
System.err.println("Error Code : " + nErrorCode); 0TqIRUz "C  
} `sLD>@m  
f;%=S:3  
BC)1FxsGf  
//停止文件下载 G.:QA}FE'  
public void siteStop() `PtfPt<{  
{ w\1K.j=>|N  
bStop = true; HP,{/ $i:  
for(int i=0;i<nStartPos.length;i++) sdBB(  
fileSplitterFetch.splitterStop(); 2-%9k)KH  
KjK-#F,@  
48)D%867.;  
} avY<~-44B  
} +' SG$<Xv  
//负责部分文件的抓取 k!V@Q!>,  
**FileSplitterFetch.java 07G'"=  
*/ X`A+/{ H  
package NetFox; l^2m7 7)  
6eQa @[.Q  
x~ E\zw  
import java.io.*; ub]s>aqy   
import java.net.*; y=2nV  
z:;yx  
hm0MO,i"  
public class FileSplitterFetch extends Thread { Y+DVwz$  
Mu@(^zW  
H`4KhdqR  
String sURL; //File URL K?Jo"oy7  
long nStartPos; //File Snippet Start Position GO3KKuQ=  
long nEndPos; //File Snippet End Position Uka(Vr:  
int nThreadID; //Thread's ID 0lU pil  
boolean bDownOver = false; //Downing is over ~!P&LZ  
boolean bStop = false; //Stop identical C,B{7s0-  
FileAccessI fileAccessI = null; //File Access interface deOk>v&U  
i.gagb  
-d[Gy- J  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6$t+Q~2G!  
{ X2`n&JE  
this.sURL = sURL; H#3Ma1z  
this.nStartPos = nStart; PY#_$ C  
this.nEndPos = nEnd; lL,0IfC,  
nThreadID = id; sj&1I.@,>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #&Rx?V  
} P"|-)d  
h>A~yDT[  
T2TWb  
public void run() >$7{H]  
{ @xr}(.  
while(nStartPos < nEndPos && !bStop) NCVhWD21|  
{ C_&ZQlgQ  
19i=kdH  
1aezlDc*  
try{ or(P?Ro  
URL url = new URL(sURL); t\O#5mo  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @%8$k[  
httpConnection.setRequestProperty("User-Agent","NetFox"); nq\~`vH|Gd  
String sProperty = "bytes="+nStartPos+"-"; cA~bH 6  
httpConnection.setRequestProperty("RANGE",sProperty); jpZ 7p ;  
Utility.log(sProperty); *JO%.QNg  
Wu)An  
91UC>]}H  
InputStream input = httpConnection.getInputStream(); _pkmHj(  
//logResponseHead(httpConnection); lr=quWDY  
]'<"qY  
|Ew&.fgz  
byte[] b = new byte[1024]; - H`, ` #{  
int nRead; M&KJZ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OG^#e+  
{ :/6u*HwZh  
nStartPos += fileAccessI.write(b,0,nRead); @Py?.H   
//if(nThreadID == 1) VP^{-mDph  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HBZtg  
} )Ut9k  
V=E5pB`Pr  
Ci?RuZ"  
Utility.log("Thread " + nThreadID + " is over!"); AIw~@*T  
bDownOver = true; :` S\p[5  
//nPos = fileAccessI.write (b,0,nRead); #(-?i\i  
} o),@I#fM  
catch(Exception e){e.printStackTrace ();} EV_u8?va  
} vAtR\ Vh  
} ]:Pkh./  
eY_BECJ+OO  
w +HKvOs5c  
//打印回应的头信息 /U="~{*-R  
public void logResponseHead(HttpURLConnection con) {<Xl57w-Q  
{ ygxaT"3"=  
for(int i=1;;i++) iThf\  
{ wvH*<,8V q  
String header=con.getHeaderFieldKey(i); x";4)u=  
if(header!=null) !X1 KOG  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F ZN}T{<  
Utility.log(header+" : "+con.getHeaderField(header)); Hqb-)8 ~  
else NYPjN9L  
break; wdRk+  
} ZSn6JV'g  
} VW:Voc  
Hm_&``='  
Pk^V6-  
public void splitterStop() #^w8Y'{?  
{ 1t7T\~ +F  
bStop = true; WDh*8!)  
} Z )X(  
6t4{aa!L|9  
, 1il&  
}  !~]'&9  
(!T\[6  
#3YYE5cB  
/* SKVQ !^o  
**FileAccess.java z*WQ=l2  
*//文件访问(定位,写) <#lNi.?.  
package NetFox; xfA@GYCfT  
import java.io.*; Cp#}x1{  
F ZfhiIf  
||#+ ^p7G  
public class FileAccessI implements Serializable{ NZuylQ)0  
RYM[{]4b5F  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {QT:1U \.  
RandomAccessFile oSavedFile; \m+;^_;5GW  
long nPos; `%=!_|  
+\Je B/F  
|L6 +e *  
public FileAccessI() throws IOException lv& y<d;  
{ 3_Mynop  
this("",0); S,#UA%V"  
} {Yv5Z.L&(  
|@dY[VK>  
l6-%)6u>  
public FileAccessI(String sName,long nPos) throws IOException /?:q9Wy  
{ OZno 3Hn  
oSavedFile = new RandomAccessFile(sName,"rw"); <#e!kWGR?  
this.nPos = nPos; -aIB_  
oSavedFile.seek(nPos); CPu~^ik  
} 8LlWXeD9  
m"~),QwF9  
K[9{]$(Z  
public synchronized int write(byte[] b,int nStart,int nLen) 9S{0vc/2@  
{ g #[,4o;  
int n = -1; b IZi3GmRF  
try{ \PK}4<x}  
oSavedFile.write(b,nStart,nLen); ,/..f!bp  
n = nLen; f/g-b]0  
} s@|TQ9e |j  
catch(IOException e) incUa;  
{ 3mXRLx=0>  
e.printStackTrace (); >('Z9<|r:  
} "@ @Z{  
7R>Pk9J  
F vHd `  
return n; /@]@Tz@'  
} )5ISkbsxD  
Yx<wYzD  
KgEfhO$W  
} xu* dPG)v  
mjbV^^>  
SgY\h{{sP  
/* JAI;7  
**SiteInfoBean.java s%t =*+L\  
*/ Z;J{&OJ3qM  
package NetFox; \m1jV>q  
<k-hRs2d  
f}+8m .g2  
public class SiteInfoBean { [^A>hs*  
K_LwYO3  
.l~g`._  
private String sSiteURL; //Site's URL $Z4IPs  
private String sFilePath; //Saved File's Path s@5r}6?M  
private String sFileName; //Saved File's Name C/A~r  
private int nSplitter; //Count of Splited Downloading File )` 90*  
\UBQ:+3  
f 7j9'k  
public SiteInfoBean() k^r-~q+NV#  
{//nSplitter的缺省值为5 1IV R4:a  
//default value of nSplitter is 5 ]LZ,>v  
this("","","",5); 'Mm=<Bh  
} $7bux 1L  
SDICN0X*  
-O?&+xIK&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ajALca4  
{ 6*=7ifS  
sSiteURL= sURL; =CjN=FM  
sFilePath = sPath; (Y$48@x  
sFileName = sName; 8S7 YVsDz"  
this.nSplitter = nSpiltter; Rz!!;<ye8  
/V)4B4  
cp<jwcc!  
} #[ch?K  
Blnc y  
f/RDo4  
public String getSSiteURL() }?XNA.Wz  
{ @m Id{w z  
return sSiteURL; sn?YD'>k  
} (w{C*iB  
e&J_uG  
S K7b]J>  
public void setSSiteURL(String value) 3Mt Alc0xp  
{ k?'<f  
sSiteURL = value; MJ0UZxnl  
} \cRe,(?O  
_4#&!b6  
KHJk}]K  
public String getSFilePath() N_),'2  
{ B!zqvShF  
return sFilePath; za oC  
} N"q C-h  
58H%#3Fy  
.WT^L2l%  
public void setSFilePath(String value) JOm6Zc  
{ BbdJR]N/!h  
sFilePath = value; K]Onb{QY  
} ;5wr5H3  
K{x FhdW  
gaXKP1m^  
public String getSFileName() CiSl 0  
{ b&1-tYV  
return sFileName; 0x/3Xz  
} >hbT'Or@  
'fkaeFzOl  
?Ok@1  
public void setSFileName(String value) czv )D\*  
{ 7yK1Q_XY>  
sFileName = value; hfuGCD6F`  
} C5^eD^[c  
-d8||X[  
@lnM%  
public int getNSplitter() ]9}T)D f'  
{ WgK|r~  
return nSplitter; mC}!;`$8p  
} 2og8VI  
) "o+wSI1  
\1p5$0z  
public void setNSplitter(int nCount) :9Vd=M6,  
{ VF<C#I  
nSplitter = nCount; BLvI[b|3gn  
} >`@yh-'r  
} r 7mg>3  
M"t=0[0DM:  
%VCfcM}5I  
/* !dW77kLTg  
**Utility.java U8 b1 sz  
*/ pM i w9}  
package NetFox; 8uO@S*)0  
M5Twulz/w  
{vJ)!'Eh  
public class Utility { iWN-X (  
l?/.uNw  
`=0J:  
public Utility() r_kw "9  
{ z]YP  
IHg)xZ  
B~u_zZE  
} f~.w2Cna  
4#qjRmt  
//线程睡眠 ClHaR  
public static void sleep(int nSecond) IFX|"3[$  
{ ?]=fC{Rh  
try{ Iy}r'#N  
Thread.sleep(nSecond); &E{5k{Y  
} UEq;}4Bo  
catch(Exception e) 8O]U&A@  
{ J9LS6~ 7  
e.printStackTrace (); 5g- apod  
} :8_`T$8i4  
} LaZF=<w(  
9rb/hkX&  
//日志 T$]2U>=<J  
public static void log(String sMsg) }eX_p6bBw  
{ ?;,Al`/^  
System.err.println(sMsg); |<.b:e\4  
} I`%=&l[v_5  
$p4aNC  
~^.&nph  
public static void log(int sMsg) a{h(BI^~  
{ S iw9_c  
System.err.println(sMsg); We]X+>BlO  
} @"s\eL,r  
} s\&_Kbw] c  
Q:~w;I  
fBH&AO$Q  
/* Et'C4od s  
**TestMethod.java bIm$7a`T  
*/ 04;y%~,}U/  
package NetFox; GtO5,d_  
F!>K8q  
P:k(=CzZ@J  
public class TestMethod { i&,U);T  
x#0C+cU  
IQ{Xj3;?y  
public TestMethod() ke>\.|HT}  
{ ///xx/weblogic60b2_win.exe ]@J}f}Mjo  
try{ 8{+~3@T  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A2&&iL=j/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "tIf$z  
SiteFileFetch fileFetch = new SiteFileFetch(bean); oz5o=gt7  
fileFetch.start(); ~+7yi4(i  
} d L%E0o  
catch(Exception e){e.printStackTrace ();} [/uKo13  
GIVs)~/Eq  
W? UCo6<m  
} <(p1 j0_Q  
J-PzIFWd  
_R(5?rG,  
public static void main(String[] args) 'v|2} T*  
{ =w A< F  
new TestMethod(); J#V `W&\,6  
} paBGJ~{=  
} j|G-9E  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五